namic behavior of the structures using different geometry of the porosity or replacing with notporous surfaces. This analysis is very interesting as t

Size: px
Start display at page:

Download "namic behavior of the structures using different geometry of the porosity or replacing with notporous surfaces. This analysis is very interesting as t"

Transcription

1 The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 212 Wind tunnel studies on the effects of porous elements on the aerodynamic behavior of civil structures M. Belloli a, D. Rocchi a, L. Rosa a, A. Zasso a a Politecnico di Milano, Dipartimento di Meccanica, via La Masa 1, 2156 Milano, Italy ABSTRACT: This paper deals with the role of the porosity on the aerodynamic behavior of two civil structures: the Spire, a tall slender tower 8.44m high, and the buttresses of a tall building. The Spire is an original architectonic complement. Its covering, made of perforated steel plates, forms and intricate three-dimensional spiral characterized by five different diameters. The buttresses connect the building core around one fourth of its height to viscous dampers at their bottom, in order to increase the overall damping value of the building. The geometry of the buttresses is characterized by a variable cross-section along the longitudinal axis, permeable to the air. Wind tunnel tests on a 1:5 scaled rigid and aeroelastic model of the Spire and on a 3:1 scaled sectional model of the buttress were carried out in order to investigate the aerodynamic behavior of the structures using different geometry of the porosity or replacing with not-porous surfaces. The analysis carried out highlights the great influence of the porosity in the dynamic response of both structures, mainly in relation to vortex shedding induced vibrations. KEYWORDS: Porous surface; Vortex Shedding; Wind Tunnel Tests; Wind Loads; Aeroelastic Model; High Slender Tower. 1 INTRODUCTION Nowadays porosity has a wide range of application in engineering and civil fields. In agricultural, porous screens have been largely used for many years in many functions: temperature regulating, shading, wind-breaking, anti-hail, anti-frost or for preventing the entrance of insects or birds. In some ventilation system, screens are used to control dust as filter function. As an alternative to these historical functions, the porosity finds new applications in civil structures. In fact modern buildings have required to reach higher energetic standards and this is achieved not only, using new construction materials, but also applying accessory elements to the structures. Porous structural elements are ones of the most common, since they have many functionalities: architectural design, temperature regulating function, shading function, wind-breaking effect and, last but not least, vortex shedding mitigation. In literature there are many experimental and numerical CFD studies about flow through porous surface, e.g. [1,2,3]. Most of them regard wind loads on structures such as greenhouses, panels or roof [4,5,6,7,8,9]; these results reveals that the wind loads on perforated structure are generally lower than those on same non-porous surfaces. More systematic studies regard flow around porous cylinders [1,11]: in particular they show how vortex shedding can be reduced or suppressed manipulating the flow around the cylinder through the application of suction or blowing. Not a great number of experimental data are on the contrary available about wind interaction with permeable accessory elements in civil structures. For instance some recent studies attest that the porosity of a surface could modifies the wake formation and reduces the intensity of the vortex shedding and the overall crosswind load [12,13]. This paper deals with the role of the porosity on the aerodynamic behavior considering as illustrative examples two civil structures: the Spire, a tall slender tower 8.44m high, and the buttresses of a tall building. Wind tunnel tests were carried out in order to investigate the aerody- 1132

2 namic behavior of the structures using different geometry of the porosity or replacing with notporous surfaces. This analysis is very interesting as the structures could be subjected to atmospheric icing which can make non-porous parts of the perforated panels and so change their aerodynamic behavior. 1.1 The Spire The Spire, which is erected on the top of a 139m new tall building, consists of a supporting lattice framework structure 8.44m high, covered with perforated steel plates. Considering the height of the building, the Spire maximum elevation from the ground is 22m (Figure 1). The external cover is not regular, but forms an intricate three-dimensional spiral characterized by five different diameters which decrease along the height of the structure. Changing the diameter along the height of the structure mitigates the vortex shedding phenomenon, but in the present case each section of the spire has an adequate length to introduce energy to the whole system and to induce oscillations of the spire to lead to fatigue damages [14,15]. Figure 1. The Spire at the top of the new tall building. Its maximum elevation from the ground is 22m. 1.2 The buttress The second structure studied in this paper are the long buttresses of a tall building, Figure 2(a). This building is an office tower 22m tall and it has a rectangular floor plan of 61.5m x 24m. The tower is characterized by two couples of external steel buttresses inclined with respect to the vertical axis and connected to the tower core around one fourth of its height along the front and the back facades. The buttresses are connected to their bottom ends to viscous dampers in order to increase the overall damping value of the building with respect to the minor side, providing beneficial effect to the base moment. The length of the buttress is 61.6m end connections included. Their geometry is characterized by a variable cross-section along the longitudinal axis made by 3 Circular Hollow Section (CHS) interconnected rigidly by steel plates (Figure 2(b)); between the transverse connections the area within the three longitudinal CHS is permeable to the air. At mid span the three CHS reach the maximum c/c distance of 1.2m (see section 3, Figure 2); whereas at the two ends the three sections converge into a single circular tube (see sections 1 and 2, Figure 2). 1133

3 The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 212 Section 2 Section 1 Section 3 Figure 2. The 22m high tall building. (a) Global view. (b) Buttress geometry and transverse typical sections. The 3D view represents the central part of the buttress (section 3). 2 EXPERIMENTAL SET-UP Wind tunnel tests were performed at the 1.5MW closed-circuit wind tunnel at the Politecnico di Milano, Italy. The large dimensions of the boundary layer test section (4m high, 14m wide and 36m long) allows a very large geometry scale to be used while maintaining lower blockage effects. The tests were performed in smooth flow condition (turbulence intensity I u < 2%) which is considered on the safe side with respect to instability and vortex shedding excitation. 2.1 The model of the Spire The experimental tests were performed using two models of the Spire: a rigid and an aeroelastic model. In this work we will focus on the results obtained on the aeroelastic model. A comparison between the results from the two models, to verify the presence of possible aeroelastic effects, can be found in [16], while a study about the local wind loads on the permeable panels by means of pressures measurements can be found in [17]. The large dimensions of the test section allowed to choose a geometry scale λ L = 1/5. The aeroelastic model was designed as a spine model, adopting the Froude similitude criteria for scale reduction: the elastic properties of the real structure were reproduced by means of an aluminum bar made up by rectangular section of four different dimensions. An external cover, constituted of 16 modules, was adopted to reproduce the wind interaction shape and to match the correctly scaled mass. A more detailed description about the aeroelastic model set-up can be found in [17], while Figure 3(a) shows the model in the test section. Great care was taken for scaling the external surface geometry and porosity: in order to guarantee the kinematic similitude the perforated panels must be scaled not geometrically but the same loss coefficient must be maintained [7]. The loss coefficient k is defined as: pu pd k = (1) ρu 2 /

4 being p u and p d respectively the upstream and the downstream static pressure on either side of the grid, ρ is the density of the air and U is the mean wind speed. This coefficient is a indicator of the resistance to flow through a porous surface, including the effects of the open area β (defined as the ratio between the area open to through flow and the total area of the panel) as well as the shape of the perforations. The pressure loss coefficients were evaluate experimentally in a smaller wind tunnel, in which its entire round cross section (diameter = 4mm) was covered by the grid being tested. (a) (b) Figure 3. (a) The aeroelastic model in wind tunnel test section. (b) The perforated panels on the real structure. In the real structure the panels have round hole perforation (radius 7.5mm) with triangular pitch of 21mm, Figure 3(b). Their open area β is 46.3% and the loss coefficient k varies between 4.5 and 4.8 (experimentally evaluated). On the models round hole perforated plates with radius.4mm and triangular pitch of 1mm were used. These plates were electrical discharge machining formed, they had an open area β=58% and a loss coefficient k very close to the real structure (4<k<4.5). Global forces measurement is carried out by means of a dynamometric six-components force-balance linked at the base of the model. The exposure angle and the reference system is shown in Figure 4(a). (a) (b) (c) Figure 4. (a) Exposure angle and reference system. (b) Heights of the cobra probes (h) and the accelerometers (Acc). (c) The aeroelastic model made completely non-porous. 1135

5 The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 212 The model was instrumented with 6 accelerometers fixed on the structural bar in order to monitor the accelerations according to its bending modes (x-dir and y-dir). Vortex shedding excitation was investigated using four Cobra Probes, a multi-hole pressure probe developed by Turbulent Flow Instrumentation (TFI). They were fixed downwind the Spire at the heights shown in Figure 4(b); the same figure shows the positions of the accelerometers. In order to evaluate the effects of the porosity on the wind loads as well as the vortex shedding excitation, some tests were duplicated making impermeable the entire external surface of the aeroelastic model, Figure 4(c). Great care has been taken in order to keep the surface roughness unchanged adding the tape on the external surface. 2.2 The model of the buttress The tests were carried out on a sectional model of the buttress (3/1 geometric scaled, aspect ratio L/B=6) realized in carbon fiber. The model is rigid and it was elastically suspended to realize a one degree of freedom system able to vibrate orthogonally to the incoming mean wind direction (cross flow direction), Figure 5. Structural modal damping was kept as low as possible in order to highlight the VIV phenomenon and it was adjustable by adding damping to the model through eddy current dampers or viscous dampers. In this way it was possible to change the Scruton Number and to investigate the oscillation amplitudes as a function of this parameter. Figure 5. Overall view of the suspended model in the test section for dynamic tests. Tests were performed at 3 angles of attack α, in according with Figure 6(a) and on different layouts. Porous screens: the gap between the cylinders is closed by a porous screen, Figure 6(b). Solid screens: the gap between the cylinders is completely closed, Figure 6(c). Different model surface finishing were also tested. (a) (b) (c) Figure 6. Sectional model of the buttresses. (a) Cross-section and wind direction angle. (b) Open, porous screens. (c) Close, solid screens. 1136

6 3 RESULTS The analysis has demonstrated that the permeability has a great importance on the aerodynamic behavior of both structures. In the following the main results from the experimental wind tunnel tests are presented. 3.1 The Spire Figure 7 shows the overall wind load at the base of the aeroelastic model of the Spire. The results are expressed in terms of the drag coefficient C D (α) and C L (α), Equation (2), where F D is the drag force and F L is the lift (side) force function of the exposition angle α, q H is the mean wind pressure at the base of the Spire and A rif is the reference area. The peak factor method for Gaussian process has been used for the evaluation of the peak values. C D, L ( ) F ( α ) D, L α = (2) q A H rif The figure shows the along-wind component C D, Figure 7(a) and the cross-wind component C L, Figure 7(b), of the overall wind load measured at the base of the aeroelastic model of the Spire in the in-service configuration (perforated panels) and making not-porous all the panels (close configuration). Due to the three dimensional external shape of the covering both coefficients manifest a great variability changing the exposition angle α. Considering the drag coefficient C D, the non-porous configuration shows a moderate increment of the mean value and a higher increment of the peak values. In particular at α=-3deg and α=-6deg the mean value is almost the same, but the peak value is nearly doubled. The effect of the porosity on cross wind coefficient is more relevant. The non-porous Spire does not manifest a modification in mean value, which stays close to zero, on the contrary the peak values show a great increment: the maximum peak occurs about at a=-9 deg, where its value is about ten-times larger than the equivalent from porous panels. The analysis of the wind load coefficients reveals that making nonporous the panels slightly increases the along-wind force on the structures and generates a strong cross-wind dynamic load. The increment of the cross wind dynamic is strictly linked to a strong vortex shedding excitation, described in the next paragraph. Drag coefficient Cd (-) Mean-Imperm. Peak-Imperm. Mean-Porous Peak-Porous Lift coefficient Cl (-) Mean-Impermeable Peak-Impermeable Mean-Porous Peak-Porous Exposition angle α (deg) Exposition angle α (deg) Figure 7. Overall wind load at the base of the Spire, smooth flow. Comparison between porous and non-porous panels. (a) Drag coefficient, C D. (b) Lift coefficient, C L (Note the difference in the y-axis scale). 1137

7 The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 212 The vortex shedding investigation has been performed analyzing the cross-wind velocities downwind the Spire measured by the four cobra probes. In the discussion of the results the crosswind velocity v i refers the probe at height h i placed downwind a section of the Spire characterized by a diameter D i. Figure 8 shows the spectra of the cross-wind velocities vi in the wake of the Spire the porous panels. The test speed was selected in order to generate from the section D2 a vortex shedding resonant with the first vibration mode of the structure (f1=5.9hz). The peak at the frequency f1 in the spectra of the component v2, Figure 8(c), confirms this condition. D4 - v4.4.2 D3 - v3.4.2 f = 8.3Hz Freq. (Hz) - (a) Freq. (Hz) - (b).2 D2 - v f = 5Hz D1 - v Freq. (Hz) - (c) Freq. (Hz) - (d) Figure 8. Aeroelastic model with porous panels. U=2.18m/s, SF. Spectra of the cross-wind velocities v i downwind the Spire (Model scale data). The section D2 has a full length scale of about 2m, a quarter of the total height of the structure, making its length not negligible compared with the respective mean diameter of about 5m. For this reason, even if changing the diameter along the height of the structure is known that mitigates the vortex shedding phenomenon, this section could have an adequate length to introduce enough energy to whole structure and induce vibrations [14,18,19]. The previous assumption, generally valid for non-porous circular surfaces, is disproved in the present case inspecting the spectra of the cross-wind velocities at the other levels. The excitation of the whole structure due to vortex shedding phenomenon is excluded by the following considerations: the spectra of the component v3, Figure 8(b), shows a peak at the Strohual frequency of the section D3 (f=8.3 Hz) and not at the first natural frequency of the model. The peaks in the spectra have a broad bandwidth, indicating a vortex shedding not fully synchronized. Lastly the crosswind displacements time histories calculated from the integration of the accelerometers signals are very low at all the levels considered (the maximum full scale peak to peak displacement is 5mm) and no regular vibrations are visible. On the contrary, the aerodynamic behavior of the Spire completely non-porous is totally different. Figure 9 shows the spectra of the cross-wind velocities vi in the wake of the Spire fully non-porous. The test speed was selected in order to have a vortex shedding generated by the section D3 resonant with the first vibration mode of the structure (f1=4.5hz). The clear narrow bandwidth peak at the frequency f1 in the spectra of the component v3, Figure 9(b), confirms this condition. A narrow bandwidth peak at the same frequency is also present in the spectrum of the component v4, Figure 9(a), while downwind the sections at the lower levels, D1 and D2, a peak is also present but it is located at the Strohual frequency of the section and not at the first natural frequency of the model, Figure 9(c-d). This analysis reveal that vortex shedding induced vibration is now present, but due to the very low wind speed the energy introduced is not enough to induce an important vibration of the entire Spire. 1138

8 .4.4 D4 - v f = 4.5Hz D3 - v f = 4.5Hz Freq. (Hz) - (a) Freq. (Hz) - (b).1 D2 - v2.5 f = 2.Hz D1 - v Freq. (Hz) - (c) Freq. (Hz) - (d) Figure 9. Aeroelastic model with panels fully non-permeable. U=1.28m/s, SF. Spectra of the cross-wind velocities v i downwind the Spire (Model scale data). The top-spire cross-wind time history displacement calculated from the integration of the accelerometers shows an evident constant vibration of the Spire due the vortex shedding excitation. The vibration is small, 2mm model equal to 1mm full scale, nevertheless since the low but very frequent wind speed, it could be enough to lead to fatigue damages to the structure. The absence of a vortex induced vibration on the permeable structure is given by the porosity: a detailed analysis by means of pressure measurements conducted in [16] has shown that permeability reduces the wind load because the air flows through the holes of the permeable panel, tending to equalize the mean pressure and attenuate the peak across the panel. As a consequence the vortex shedding excitation is strongly reduced. 3.2 Isozaki tower buttresses Vortex induced vibration (VIV) tests were performed on the sectional model of the buttress. Aim of the tests was to compare the aerodynamic behavior of the buttresses using different screens layouts, different porosity in the area permeable to the air and different surface roughness. Aerodynamic stability of the buttress shape has been also investigated by studying the aerodynamic damping trend increasing the mean wind speed. The results are presented in function of the Scruton Number, defined as Eq.(3), where m is the mass per unit length of the body, h s critical damping ratio, ρ is the air density and B is the overall dimension of the cross section. 2π mhs Sc = (3) 2 ρb The solid screens layout (Figure 6(c)) was firstly investigated. This configuration highlighted significant problems related to the fluid-structure interaction. In particular, considering the angle of attack α=-3deg (Figure 6(a)), the model showed significant vortex induced vibrations with also the presence of instability phenomena that led to large uncontrolled flow-induced vibrations unsuitable at low Scruton number (Sc=.1, Figure 1(a)) and even at high value of Scruton number (u/b=4.5% at Sc=23, where u is the experimental displacement and B the model characteristic dimension, Figure 1(b)). Oscillations were still present even if the Scruton number was increased up to

9 The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 212 Non-dimensional oscillation amplitude u/b (%) Test stopped Test stopped Time (s) Time (s) (a) (b) Figure 1. (a) Solid screens layout, α=-3deg, instability and VIV. (a) Sc=.1. (b) Sc=25. The choice was to use porous screens as an alternative configuration to the "solid screens". These screens have round hole perforation (radius 5mm) with triangular pitch of 14mm and porosity β=46%. This layout was stable at the angles of attack α=deg and α=3deg, while vortex induced vibrations were still present at α=-3deg. Figure 11(b) shows the non-dimensional oscillation amplitude u/b (%) function of the Scruton Number Sc: it is possible to see that increasing the structural damping to provide a Scruton number higher than 12 the oscillations stopped. The stability of the structure was checked also changing the surface roughness of the model. Non-dimensional oscillation amplitude u/b (%) >7.5% Scruton number (-) Figure 11. Porous screens layout, α=3deg. VIV in function of Scruton number at the most critical angle of attack. Non-dimensional oscillation amplitude u/b (%) Porous screens -3 Porous screens -3 rough 4 CONCLUSIONS The analysis has demonstrated that the permeability has a great importance on the aerodynamic behavior of the structures considered in the present work. Tests showed that the porosity of the external surface gives advance on both the mean load reduction as well vortex shedding attenuation. This is due to the passage of the flow through the panels which modifies locally the pressure distribution and, as a result, the wind loads and the dynamic response of the whole 114

10 structure. The realistic relevance of this analysis is even that the structures, due to their position, can be subjected to atmospheric icing which can make non-porous parts of the external panels. In particular, the Spire with porous external panels is not affected by vortex shedding induced vibrations. since the energy introduced by the wind is not enough the induce a synchronous vibration of the entire structure. On the contrary the Spire fully non-porous suffers of a strong vortex shedding induced vibration which, due to the presence of four different diameter along the height, occur in a wide range of wind speeds. The second structure studied were the long buttresses of a tall building. Also in this case the porosity of the screen between the cylinders gave stability to the structure which, if completely closed, suffered of significant vortex induced vibrations with also the presence of instability phenomena. 5 REFERENCES 1. M. Teitel, D. Dvorkin, Y. Haim, J. Tanny and I. Seginer, Comparison of measured and simulated flow through screens: Effects of screen inclination and porosity, Biosystems Engineering, 14 (29), pp J. L. Santiago, F. Martin, A. Cuerva, N. Bezdenejnykh and A. Sanz-Andres, 'Experimental and numerical study of wind flow behind windbreaks', Atmospheric Environment, 41 (27), pp A. F. Miguel, 'Airflow through porous screens: From theory to practical considerations', Energy and Buildings, 28 (1998), pp Briassoulis, D., A. Mistriotis, and A. Giannoulis, Wind forces on porous elevated panels. Journal of Wind Engineering and Industrial Aerodynamics, (12): p D. Briassoulis, A. Mistriotis and A. Giannoulis, 'Wind forces on porous elevated panels', Journal of Wind Engineering and Industrial Aerodynamics, 98 (21), pp A. P. Robertson, P. Roux, J. Gratraud, G. Scarascia, S. Castellano, M. Dufresne de Virel and P. Palier, 'Wind pressures on permeably and impermeably-clad structures', Journal of Wind Engineering and Industrial Aerodynamics, 9 (22), pp C. W. Letchford, 'Wind loads on rectangular signboards and hoardings', Journal of Wind Engineering and Industrial Aerodynamics, 89 (21), pp C. W. Letchford, A. Row, A. Vitale and J. Wolbers, 'Mean wind loads on porous canopy roofs', Journal of Wind Engineering and Industrial Aerodynamics, 84 (2), pp G. M. Richardson, 'A permeable windbreak: its micro-environment and its effect on structural loads', Journal of Agricultural Engineering Research, 38 (1987), pp J. C. K. Cheung and W. H. Melbourne, 'Wind loading on a porous roof', Journal of Wind Engineering and Industrial Aerodynamics, 29 (1988), pp J. H. M. Fransson, P. Konieczny and P. H. Alfredsson, 'Flow around a porous cylinder subject to continuous suction or blowing', Journal of Fluids and Structures, 19 (24), pp L. Mathelin, F. Bataille and A. Lallemand, 'Near wake of a circular cylinder submitted to blowing - II: Impact on the dynamics', International Journal of Heat and Mass Transfer, 44 (21), pp C. Zheng and Y. Zhang, 'Numerical investigation of wind-load reduction for a high-rise building by blowing control', Jianzhu Jiegou Xuebao/Journal of Building Structures, 31 (21), pp H. Baek and G. E. Karniadakis, 'Suppressing vortex-induced vibrations via passive means', Journal of Fluids and Structures, 25 (29), pp P. A. Irwin, 'Wind engineering challenges of the new generation of super-tall buildings', Journal of Wind Engineering and Industrial Aerodynamics, 97 (29), pp M. P. Repetto and G. Solari, 'Wind-induced fatigue collapse of real slender structures', Engineering Structures, 32 (21), pp M. Belloli, L. Rosa and A. Zasso, 'Wind loads and vortex shedding analysis on the effects of the porosity on an high slender tower', submitted to: Journal of Wind Engineering and Industrial Aerodynamics (212). 17. M. Belloli, L. Rosa and A. Zasso, 'A comparative study of the wind loads on a slender tower with porous surface', submitted to: Wind and Structure (211). 18. Y.-M. Kim, K.-P. You and N.-H. Ko, 'Across-wind responses of an aeroelastic tapered tall building', Journal of Wind Engineering and Industrial Aerodynamics, 96 (28), pp K. Shimada and K. Hibi, 'Estimation of wind loads for a super-tall building (SSH)', The Structural Design of Tall Buildings, 4 (1995), pp

Geometry Modification For Minimizing The Aeroelastics Effect

Geometry Modification For Minimizing The Aeroelastics Effect Geometry Modification For Minimizing The Aeroelastics Effect Fariduzzaman a, Subagyo a, Fadilah Hasim a and Matza Gusto Andika a a Aero-Gas dynamics and Vibration Laboratory (LAGG), BPPT, PUSPIPTEK, Serpong

More information

Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge

Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge Aerodynamic Measures for the Vortex-induced Vibration of π-shape Composite Girder in Cable-stayed Bridge *Feng Wang 1), Jialing Song 2), Tuo Wu 3), and Muxiong Wei 4) 1), 2, 3), 4) Highway School, Chang

More information

Quantification of the Effects of Turbulence in Wind on the Flutter Stability of Suspension Bridges

Quantification of the Effects of Turbulence in Wind on the Flutter Stability of Suspension Bridges Quantification of the Effects of Turbulence in Wind on the Flutter Stability of Suspension Bridges T. Abbas 1 and G. Morgenthal 2 1 PhD candidate, Graduate College 1462, Department of Civil Engineering,

More information

PRESSURE FLUCTUATIONS ACTING ON A TAPERED TALL BUILDING

PRESSURE FLUCTUATIONS ACTING ON A TAPERED TALL BUILDING The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 29, Taipei, Taiwan PRESSURE FLUCTUATIONS ACTING ON A TAPERED TALL BUILDING Young-Moon Kim 1, Ki-Pyo You 1, Jang-Youl You 2 and Chang-Hyun

More information

The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 2012 Wind tunnel measurements

The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 2012 Wind tunnel measurements The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 2012 Wind tunnel measurements of aeroelastic guyed mast models a, Tomasz Lipecki

More information

An Overview of Wind Engineering Where Climate Meets Design

An Overview of Wind Engineering Where Climate Meets Design An Overview of Wind Engineering Where Climate Meets Design Presented by Derek Kelly, M.Eng., P.Eng. Principal/Project Manager www.rwdi.com RWDI Leadership & Consulting Expertise RWDI Consulting Engineers

More information

SPECTRAL CHARACTERISTICS OF FLUCTUATING WIND LOADS ON A SEPARATE TWIN-BOX DECK WITH CENTRAL SLOT

SPECTRAL CHARACTERISTICS OF FLUCTUATING WIND LOADS ON A SEPARATE TWIN-BOX DECK WITH CENTRAL SLOT The Seventh Asia-Pacific Conference on Wind Engineering, November 8-, 009, Taipei, Taiwan SPECTRAL CHARACTERISTICS OF FLUCTUATING WIND LOADS ON A SEPARATE TWIN-BOX DEC WITH CENTRAL SLOT Le-Dong Zhu, Shui-Bing

More information

GEA FOR ADVANCED STRUCTURAL DYNAMIC ANALYSIS

GEA FOR ADVANCED STRUCTURAL DYNAMIC ANALYSIS SMART SOLUTIONS FOR VIBRATION MONITORING GEA FOR ADVANCED STRUCTURAL DYNAMIC ANALYSIS ANALYSIS OF CIVIL STRUCTURES - EXPO MERLATA PEDESTRIAN BRIDGE ABSTRACT Civil structures and in particular bridges and

More information

WIND-INDUCED LOADS OVER DOUBLE CANTILEVER BRIDGES UNDER CONSTRUCTION

WIND-INDUCED LOADS OVER DOUBLE CANTILEVER BRIDGES UNDER CONSTRUCTION WIND-INDUCED LOADS OVER DOUBLE CANTILEVER BRIDGES UNDER CONSTRUCTION S. Pindado, J. Meseguer, J. M. Perales, A. Sanz-Andres and A. Martinez Key words: Wind loads, bridge construction, yawing moment. Abstract.

More information

Influence of rounding corners on unsteady flow and heat transfer around a square cylinder

Influence of rounding corners on unsteady flow and heat transfer around a square cylinder Influence of rounding corners on unsteady flow and heat transfer around a square cylinder S. K. Singh Deptt. of Mech. Engg., M. B. M. Engg. College / J. N. V. University, Jodhpur, Rajasthan, India Abstract

More information

Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the Vortex Generators

Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the Vortex Generators Second International Symposium on Marine Propulsors smp 11, Hamburg, Germany, June 2011 Numerical and Experimental Investigation of the Possibility of Forming the Wake Flow of Large Ships by Using the

More information

MEASUREMENTS ON THE SURFACE WIND PRESSURE CHARACTERISTICS OF TWO SQUARE BUILDINGS UNDER DIFFERENT WIND ATTACK ANGLES AND BUILDING GAPS

MEASUREMENTS ON THE SURFACE WIND PRESSURE CHARACTERISTICS OF TWO SQUARE BUILDINGS UNDER DIFFERENT WIND ATTACK ANGLES AND BUILDING GAPS BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 2-24 28 MEASUREMENTS ON THE SURFACE WIND PRESSURE CHARACTERISTICS OF TWO SQUARE BUILDINGS UNDER DIFFERENT

More information

RESILIENT INFRASTRUCTURE June 1 4, 2016

RESILIENT INFRASTRUCTURE June 1 4, 2016 RESILIENT INFRASTRUCTURE June 1 4, 2016 CASE STUDIES ON THE IMPACT OF SURROUNDING BUILDINGS ON WIND-INDUCED RESPONSE John Kilpatrick Rowan Williams Davies and Irwin, Guelph, Ontario, Canada ABSTRACT In

More information

THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC!

THE BRIDGE COLLAPSED IN NOVEMBER 1940 AFTER 4 MONTHS OF ITS OPENING TO TRAFFIC! OUTLINE TACOMA NARROWS BRIDGE FLOW REGIME PAST A CYLINDER VORTEX SHEDDING MODES OF VORTEX SHEDDING PARALLEL & OBLIQUE FLOW PAST A SPHERE AND A CUBE SUMMARY TACOMA NARROWS BRIDGE, USA THE BRIDGE COLLAPSED

More information

Experimental Investigation Of Flow Past A Rough Surfaced Cylinder

Experimental Investigation Of Flow Past A Rough Surfaced Cylinder (AET- 29th March 214) RESEARCH ARTICLE OPEN ACCESS Experimental Investigation Of Flow Past A Rough Surfaced Cylinder Monalisa Mallick 1, A. Kumar 2 1 (Department of Civil Engineering, National Institute

More information

Pressure coefficient on flat roofs of rectangular buildings

Pressure coefficient on flat roofs of rectangular buildings Pressure coefficient on flat roofs of rectangular buildings T. Lipecki 1 1 Faculty of Civil Engineering and Architecture, Lublin University of Technology, Poland. t.lipecki@pollub.pl Abstract The paper

More information

PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADE WITH WINGLETS ON ROTATING CONDITION USING WIND TUNNEL

PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADE WITH WINGLETS ON ROTATING CONDITION USING WIND TUNNEL International Journal of Mechanical and Production Engineering Research and Development (IJMPERD ) ISSN 2249-6890 Vol.2, Issue 2 June 2012 1-10 TJPRC Pvt. Ltd., PRESSURE DISTRIBUTION OF SMALL WIND TURBINE

More information

Numerical Analysis of Wind loads on Tapered Shape Tall Buildings

Numerical Analysis of Wind loads on Tapered Shape Tall Buildings IJSTE - International Journal of Science Technology & Engineering Volume 1 Issue 11 May 2015 ISSN (online): 2349-784X Numerical Analysis of Wind loads on Tapered Shape Tall Buildings Ashwin G Hansora Assistant

More information

Along and Across Wind Loads Acting on Tall Buildings

Along and Across Wind Loads Acting on Tall Buildings Along and Across Wind Loads Acting on Tall Buildings Aiswaria G. R* and Dr Jisha S. V** *M Tech student, Structural Engineering, Mar Baselios College of Engineering and Technology, Kerala aiswariagr@gmail.com

More information

leading edge, where the flow is fully separated. Both for the means and peaks, smooth flow leads to the highest values. A good correlation between cav

leading edge, where the flow is fully separated. Both for the means and peaks, smooth flow leads to the highest values. A good correlation between cav The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 22 Towards a better understanding of pressure equalization Carine van Bentum a,

More information

CFD AND EXPERIMENTAL STUDY OF AERODYNAMIC DEGRADATION OF ICED AIRFOILS

CFD AND EXPERIMENTAL STUDY OF AERODYNAMIC DEGRADATION OF ICED AIRFOILS Colloquium FLUID DYNAMICS 2008 Institute of Thermomechanics AS CR, v.v.i., Prague, October 22-24, 2008 p.1 CFD AND EXPERIMENTAL STUDY OF AERODYNAMIC DEGRADATION OF ICED AIRFOILS Vladimír Horák 1, Dalibor

More information

AE Dept., KFUPM. Dr. Abdullah M. Al-Garni. Fuel Economy. Emissions Maximum Speed Acceleration Directional Stability Stability.

AE Dept., KFUPM. Dr. Abdullah M. Al-Garni. Fuel Economy. Emissions Maximum Speed Acceleration Directional Stability Stability. Aerodynamics: Introduction Aerodynamics deals with the motion of objects in air. These objects can be airplanes, missiles or road vehicles. The Table below summarizes the aspects of vehicle performance

More information

EXPERIMENTAL STUDY OF WIND PRESSURES ON IRREGULAR- PLAN SHAPE BUILDINGS

EXPERIMENTAL STUDY OF WIND PRESSURES ON IRREGULAR- PLAN SHAPE BUILDINGS BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 2-24 8 EXPERIMENTAL STUDY OF WIND PRESSURES ON IRREGULAR- PLAN SHAPE BUILDINGS J. A. Amin and A. K. Ahuja

More information

Journal of Engineering Science and Technology Review 9 (5) (2016) Research Article. CFD Simulations of Flow Around Octagonal Shaped Structures

Journal of Engineering Science and Technology Review 9 (5) (2016) Research Article. CFD Simulations of Flow Around Octagonal Shaped Structures Jestr Journal of Engineering Science and Technology Review 9 (5) (2016) 72-76 Research Article JOURNAL OF Engineering Science and Technology Review www.jestr.org CFD Simulations of Flow Around Octagonal

More information

EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES

EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES EXPERIMENTAL INVESTIGATION OF WAKE SURVEY OVER A CYLINDER WITH DIFFERENT SURFACE PROFILES Abdul Ahad Khan 1, Abhishek M. B 2, Tresa Harsha P George 3 1 Under Graduate student, Department of Aeronautical

More information

Analysis of wind resistance of high-rise building structures based on computational fluid dynamics simulation technology

Analysis of wind resistance of high-rise building structures based on computational fluid dynamics simulation technology International Journal of Heat and Technology Vol. 36, No. 1, March, 18, pp. 376-38 Journal homepage: http://iieta.org/journals/ijht Analysis of wind resistance of high-rise building structures based on

More information

DESIGN AND CHARACTERISTICS OF A LARGE BOUNDARY- LAYER WIND TUNNEL WITH TWO TEST SECTIONS

DESIGN AND CHARACTERISTICS OF A LARGE BOUNDARY- LAYER WIND TUNNEL WITH TWO TEST SECTIONS The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 2009, Taipei, Taiwan DESIGN AND CHARACTERISTICS OF A LARGE BOUNDARY- LAYER WIND TUNNEL WITH TWO TEST SECTIONS Kai Chen 1, Xin-Yang

More information

AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING

AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING ICAS 2002 CONGRESS AERODYNAMIC CHARACTERISTICS OF SPIN PHENOMENON FOR DELTA WING Yoshiaki NAKAMURA (nakamura@nuae.nagoya-u.ac.jp) Takafumi YAMADA (yamada@nuae.nagoya-u.ac.jp) Department of Aerospace Engineering,

More information

ITTC Recommended Procedures and Guidelines

ITTC Recommended Procedures and Guidelines Page 1 of 6 Table of Contents 1. PURPOSE...2 2. PARAMETERS...2 2.1 General Considerations...2 3 DESCRIPTION OF PROCEDURE...2 3.1 Model Design and Construction...2 3.2 Measurements...3 3.5 Execution of

More information

AN EXPERIMENTAL STUDY OF THE EFFECTS OF SWEPT ANGLE ON THE BOUNDARY LAYER OF THE 2D WING

AN EXPERIMENTAL STUDY OF THE EFFECTS OF SWEPT ANGLE ON THE BOUNDARY LAYER OF THE 2D WING AN EXPERIMENTAL STUDY OF THE EFFECTS OF SWEPT ANGLE ON THE BOUNDARY LAYER OF THE 2D WING A. Davari *, M.R. Soltani, A.Tabrizian, M.Masdari * Assistant Professor, Department of mechanics and Aerospace Engineering,

More information

2013 Wall of Wind (WoW) Contest Informational Workshop

2013 Wall of Wind (WoW) Contest Informational Workshop 2013 Wall of Wind (WoW) Contest Informational Workshop Presented By: Ioannis Zisis February 22, 2013 With Contributions By: Dr. Girma Bitsuamlak, Roy Liu, Walter Conklin, Dr. Arindam Chowdhury, Jimmy Erwin,

More information

EFFECTS OF SIDEWALL OPENINGS ON THE WIND LOADS ON PIPE-FRAMED GREENHOUSES

EFFECTS OF SIDEWALL OPENINGS ON THE WIND LOADS ON PIPE-FRAMED GREENHOUSES The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 29, Taipei, Taiwan EFFECTS OF SIDEWALL OPENINGS ON THE WIND LOADS ON PIPE-FRAMED GREENHOUSES Yasushi Uematsu 1, Koichi Nakahara 2,

More information

Pressure distribution of rotating small wind turbine blades with winglet using wind tunnel

Pressure distribution of rotating small wind turbine blades with winglet using wind tunnel Journal of Scientific SARAVANAN & Industrial et al: Research PRESSURE DISTRIBUTION OF SMALL WIND TURBINE BLADES WITH WINGLET Vol. 71, June 01, pp. 45-49 45 Pressure distribution of rotating small wind

More information

JOURNAL PUBLICATIONS

JOURNAL PUBLICATIONS 1 JOURNAL PUBLICATIONS 71. Lee, T., Mageed, A., Siddiqui, B. and Ko, L.S., (2016) Impact of ground proximity on aerodynamic properties of an unsteady NACA 0012 airfoil, submitted to Journal of Aerospace

More information

An Experimental Study of Vortex Shedding Behind a Bluff Body in a Water Channel

An Experimental Study of Vortex Shedding Behind a Bluff Body in a Water Channel An Experimental Study of Vortex Shedding Behind a Bluff Body in a Water Channel ¹Meghanadhan C A, ² Sunil A S ¹PG Scholar, ² Associate Prof. Govt Engineering College Thrissur, Kerala,India Abstract-When

More information

Surrounding buildings and wind pressure distribution on a high rise building

Surrounding buildings and wind pressure distribution on a high rise building Surrounding buildings and wind pressure distribution on a high rise building Conference or Workshop Item Accepted Version Luo, Z. (2008) Surrounding buildings and wind pressure distribution on a high rise

More information

Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft

Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft , July 1-3, 2015, London, U.K. Aerodynamic Analysis of Blended Winglet for Low Speed Aircraft Pooja Pragati, Sudarsan Baskar Abstract This paper provides a practical design of a new concept of massive

More information

EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE

EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE 24 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES EXPERIMENTAL ANALYSIS OF THE CONFLUENT BOUNDARY LAYER BETWEEN A FLAP AND A MAIN ELEMENT WITH SAW-TOOTHED TRAILING EDGE Lemes, Rodrigo Cristian,

More information

Fire safety of staircases in multi-storey buildings The results of measurements in Buildings and Simulations

Fire safety of staircases in multi-storey buildings The results of measurements in Buildings and Simulations Fire safety of staircases in multi-storey buildings The results of measurements in Buildings and Simulations Grzegorz Kubicki, Ph.D. Department of Environmental Engineering, Warsaw University of Technology

More information

Wind tunnel acoustic testing of wind generated noise on building facade elements

Wind tunnel acoustic testing of wind generated noise on building facade elements See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/307638896 Wind tunnel acoustic testing of wind generated noise on building facade elements

More information

Design process to evaluate potential of wind noise at façade elements

Design process to evaluate potential of wind noise at façade elements Design process to evaluate potential of wind noise at façade elements Dr.Cristina Paduano 1, Dr.Jennifer Keenahan 1, Réamonn Mac Réamoinn 1 1 Arup, 50 Ringsend Road, Dublin 4, Ireland email: cristina.paduano@arup.com,

More information

SEMI-SPAN TESTING IN WIND TUNNELS

SEMI-SPAN TESTING IN WIND TUNNELS 25 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES SEMI-SPAN TESTING IN WIND TUNNELS S. Eder, K. Hufnagel, C. Tropea Chair of Fluid Mechanics and Aerodynamics, Darmstadt University of Technology

More information

NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING EDGE AIRFOIL

NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING EDGE AIRFOIL BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, 20-24 2008 NUMERICAL SIMULATION OF ACTIVE FLOW CONTROL BASED ON STREAMWISE VORTICES FOR A BLUNT TRAILING

More information

Conditions for occurrence of vortex shedding on a large cable stayed bridge. Full scale data from monitoring system

Conditions for occurrence of vortex shedding on a large cable stayed bridge. Full scale data from monitoring system Conditions for occurrence of vortex shedding on a large cable stayed bridge. Full scale data from monitoring system O. Flamand 1, F. De Oliveira 1 and A. Stathopoulos-Vlamis, P. Papanikolas 2 1 Centre

More information

The Usage of Propeller Tunnels For Higher Efficiency and Lower Vibration. M. Burak Şamşul

The Usage of Propeller Tunnels For Higher Efficiency and Lower Vibration. M. Burak Şamşul The Usage of Propeller Tunnels For Higher Efficiency and Lower Vibration M. Burak Şamşul ITU AYOC 2014 - Milper Pervane Teknolojileri Company Profile MILPER is established in 2011 as a Research and Development

More information

Basis of Structural Design

Basis of Structural Design Basis of Structural Design Course 10 Actions on structures: Wind loads Other loads Course notes are available for download at http://www.ct.upt.ro/users/aurelstratan/ Wind loading: normative references

More information

NUMERICAL SIMULATION OF WIND INTERFERENCE EFFECT

NUMERICAL SIMULATION OF WIND INTERFERENCE EFFECT NUMERICAL SIMULATION OF WIND INTERFERENCE EFFECT FOR A STADIUM AND A GYMNASIUM Gang Xu 1, Xing-qian Peng 2, Li Wu 1, Hai Zhu 1 1 Graduate student, College of Civil Engineering, Huaqiao University, Quanzhou,

More information

CFD Study of Solid Wind Tunnel Wall Effects on Wing Characteristics

CFD Study of Solid Wind Tunnel Wall Effects on Wing Characteristics Indian Journal of Science and Technology, Vol 9(45), DOI :10.17485/ijst/2016/v9i45/104585, December 2016 ISSN (Print) : 0974-6846 ISSN (Online) : 0974-5645 CFD Study of Solid Wind Tunnel Wall Effects on

More information

Wind Flow Validation Summary

Wind Flow Validation Summary IBHS Research Center Validation of Wind Capabilities The Insurance Institute for Business & Home Safety (IBHS) Research Center full-scale test facility provides opportunities to simulate natural wind conditions

More information

FLOW CONSIDERATIONS IN INDUSTRIAL SILENCER DESIGN

FLOW CONSIDERATIONS IN INDUSTRIAL SILENCER DESIGN FLOW CONSIDERATIONS IN INDUSTRIAL SILENCER DESIGN George Feng, Kinetics Noise Control, Inc., 3570 Nashua Drive, Mississauga, Ontario Vadim Akishin, Kinetics Noise Control, Inc., 3570 Nashua Drive, Mississauga,

More information

Journal of Engineering Science and Technology Review 6 (3) (2013) Research Article

Journal of Engineering Science and Technology Review 6 (3) (2013) Research Article Jestr Journal of Engineering Science and Technology Review 6 (3) (013) 105-110 Research Article JOURNAL OF Engineering Science and Technology Review www.jestr.org Lift and Drag on Cylinder of Octagonal

More information

Critical Gust Pressures on Tall Building Frames-Review of Codal Provisions

Critical Gust Pressures on Tall Building Frames-Review of Codal Provisions Dr. B.Dean Kumar Dept. of Civil Engineering JNTUH College of Engineering Hyderabad, INDIA bdeankumar@gmail.com Dr. B.L.P Swami Dept. of Civil Engineering Vasavi College of Engineering Hyderabad, INDIA

More information

NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT

NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT - 277 - NUMERICAL INVESTIGATION OF THE FLOW BEHAVIOUR IN A MODERN TRAFFIC TUNNEL IN CASE OF FIRE INCIDENT Iseler J., Heiser W. EAS GmbH, Karlsruhe, Germany ABSTRACT A numerical study of the flow behaviour

More information

Preliminary Design Review (PDR) Aerodynamics #2 AAE-451 Aircraft Design

Preliminary Design Review (PDR) Aerodynamics #2 AAE-451 Aircraft Design Preliminary Design Review (PDR) Aerodynamics #2 AAE-451 Aircraft Design Aircraft Geometry (highlight any significant revisions since Aerodynamics PDR #1) Airfoil section for wing, vertical and horizontal

More information

A Study on the Distribution of the Peak Wind Pressure Coefficient for the Wind Resistant Design of Rooftop Hoardings in High-rise Buildings

A Study on the Distribution of the Peak Wind Pressure Coefficient for the Wind Resistant Design of Rooftop Hoardings in High-rise Buildings International Journal of Engineering Research and Technology. ISSN 0974-3154 Volume 11, Number 10 (2018), pp. 1583-1594 International Research Publication House http://www.irphouse.com A Study on the Distribution

More information

EXPERIMENTAL RESEARCH ON DETERMINATION OF DRAG COEFFICIENT OF THE GREENHOUSES LOCATED ON ROOFS OF BUILDINGS

EXPERIMENTAL RESEARCH ON DETERMINATION OF DRAG COEFFICIENT OF THE GREENHOUSES LOCATED ON ROOFS OF BUILDINGS Bulletin of the Transilvania University of Braşov Series II: Forestry Wood Industry Agricultural Food Engineering Vol. 9 (58) No.1-2016 EXPERIMENTAL RESEARCH ON DETERMINATION OF DRAG COEFFICIENT OF THE

More information

VORTEX SHEDDING INDUCED VIBRATIONS OF A LIGHT MAST

VORTEX SHEDDING INDUCED VIBRATIONS OF A LIGHT MAST BBAA VI International Colloquium on: Bluff Bodies Aerodynamics & Applications Milano, Italy, July, -4 8 VORTEX SHEDDING INDUCED VIBRATIONS OF A LIGHT MAST Bjarni Bessason, and Jónas Thór Snaæbjörnsson

More information

Research Article Influence of Turbulence, Orientation, and Site Configuration on the Response of Buildings to Extreme Wind

Research Article Influence of Turbulence, Orientation, and Site Configuration on the Response of Buildings to Extreme Wind e Scientific World Journal, Article D 178465, 15 pages http://dx.doi.org/1.1155/214/178465 Research Article nfluence of Turbulence, Orientation, and Site Configuration on the Response of Buildings to Extreme

More information

RESILIENT INFRASTRUCTURE June 1 4, 2016

RESILIENT INFRASTRUCTURE June 1 4, 2016 RESILIENT INFRASTRUCTURE June 4, 26 EFFECT OF WIND SPEED AND TERRAIN EXPOSURE ON THE WIND PRESSURES FOR ELEVATED STEEL CONICAL TANKS Ahmed Musa Ph.D Candidate, Western University, Canada Haitham Aboshosha

More information

Wind effects on tall building frames-influence of dynamic parameters

Wind effects on tall building frames-influence of dynamic parameters Indian Journal of Science and Technology Vol. 3 No. 5 (May 21) ISSN: 974-6846 583 Wind effects on tall building frames-influence of dynamic parameters B. Dean Kumar 1 and B.L.P. Swami 2 1 Department of

More information

External Pressure Coefficients on Saw-tooth and Mono-sloped Roofs

External Pressure Coefficients on Saw-tooth and Mono-sloped Roofs External Pressure Coefficients on Saw-tooth and Mono-sloped Roofs Authors: Bo Cui, Ph.D. Candidate, Clemson University, 109 Lowry Hall, Clemson, SC 9634-0911, boc@clemson.edu David O. Prevatt, Assistant

More information

Application of pushover analysis in estimating seismic demands for large-span spatial structure

Application of pushover analysis in estimating seismic demands for large-span spatial structure 28 September 2 October 2009, Universidad Politecnica de Valencia, Spain Alberto DOMINGO and Carlos LAZARO (eds.) Application of pushover analysis in estimating seismic demands for large-span spatial structure

More information

Effects of wind incidence angle on wind pressure distribution on square plan tall buildings

Effects of wind incidence angle on wind pressure distribution on square plan tall buildings J. Acad. Indus. Res. Vol. 1(12) May 2013 747 RESEARCH ARTICLE ISSN: 2278-5213 Effects of wind incidence angle on wind pressure distribution on square plan tall buildings S.K. Verma 1, A.K. Ahuja 2* and

More information

The Effect of Von Karman Vortex Street on Building Ventilation

The Effect of Von Karman Vortex Street on Building Ventilation The Effect of Von Karman Vortex Street on Building Ventilation P.Praveen Kumar Abstract This paper deals with the utilisation of the von Karman vortex street principle to maximise air flow into buildings.

More information

Vibration Analysis and Test of Backup Roll in Temper Mill

Vibration Analysis and Test of Backup Roll in Temper Mill Sensors & Transducers 2013 by IFSA http://www.sensorsportal.com Vibration Analysis and Test of Backup Roll in Temper Mill Yuanmin Xie College of Machinery and Automation, Wuhan University of Science and

More information

Tim Lee s journal publications

Tim Lee s journal publications Tim Lee s journal publications 82. Lee, T., and Tremblay-Dionne, V., (2018) Impact of wavelength and amplitude of a wavy ground on a static NACA 0012 airfoil submitted to Journal of Aircraft (paper in

More information

Wind Tunnel Study on Spanwise Correlation of Aerodynamic Forces on a 5:1 Rectangular Cylinder

Wind Tunnel Study on Spanwise Correlation of Aerodynamic Forces on a 5:1 Rectangular Cylinder The Eighth Asia-Pacific Conference on Wind Engineering, December 10 1, 2013, Chennai, India Wind Tunnel Study on Spanwise Correlation of Aerodynamic Forces on a 5:1 Rectangular Cylinder Xiaobing Liu 1,

More information

Experimental investigation on the influence of wind direction on the aerodynamic loads acting on low aspect-ratio triangular prisms

Experimental investigation on the influence of wind direction on the aerodynamic loads acting on low aspect-ratio triangular prisms Experimental investigation on the influence of wind direction on the aerodynamic loads acting on low aspect-ratio triangular prisms Giacomo Valerio Iungo and Guido Buresti Department of Aerospace Engineering,

More information

Lehigh-FIU Hybrid Wind Simulation Developments

Lehigh-FIU Hybrid Wind Simulation Developments Lehigh-FIU Hybrid Wind Simulation Developments 2018 NSF Lehigh-FIU NHERI Experimental Facilities User Workshop December 3 rd, 2018 Amal Elawady, PhD Assistant Professor Department of Civil and Environmental

More information

Wind Loading Code for Building Design in Thailand

Wind Loading Code for Building Design in Thailand Wind Loading Code for Building Design in Thailand Virote Boonyapinyo a, Panitan Lukkunaprasit b Pennung Warnitchai c and Phoonsak Pheinsusom d a Associate Professor, Department of Civil Engineering, Thammasat

More information

EFFECT OF CORNER CUTOFFS ON FLOW CHARACTERISTICS AROUND A SQUARE CYLINDER

EFFECT OF CORNER CUTOFFS ON FLOW CHARACTERISTICS AROUND A SQUARE CYLINDER EFFECT OF CORNER CUTOFFS ON FLOW CHARACTERISTICS AROUND A SQUARE CYLINDER Yoichi Yamagishi 1, Shigeo Kimura 1, Makoto Oki 2 and Chisa Hatayama 3 ABSTRACT It is known that for a square cylinder subjected

More information

A comparison of NACA 0012 and NACA 0021 self-noise at low Reynolds number

A comparison of NACA 0012 and NACA 0021 self-noise at low Reynolds number A comparison of NACA 12 and NACA 21 self-noise at low Reynolds number A. Laratro, M. Arjomandi, B. Cazzolato, R. Kelso Abstract The self-noise of NACA 12 and NACA 21 airfoils are recorded at a Reynolds

More information

High Swept-back Delta Wing Flow

High Swept-back Delta Wing Flow Advanced Materials Research Submitted: 2014-06-25 ISSN: 1662-8985, Vol. 1016, pp 377-382 Accepted: 2014-06-25 doi:10.4028/www.scientific.net/amr.1016.377 Online: 2014-08-28 2014 Trans Tech Publications,

More information

AERODYNAMIC FEATURES AS AUXILIARY ARCHITECTURE

AERODYNAMIC FEATURES AS AUXILIARY ARCHITECTURE N. Gu, S. Watanabe, H. Erhan, M. Hank Haeusler, W. Huang, R. Sosa (eds.), Rethinking Comprehensive Design: Speculative Counterculture, Proceedings of the 19th International Conference on Computer- Aided

More information

AF100. Subsonic Wind Tunnel AERODYNAMICS. Open-circuit subsonic wind tunnel for a wide range of investigations into aerodynamics

AF100. Subsonic Wind Tunnel AERODYNAMICS. Open-circuit subsonic wind tunnel for a wide range of investigations into aerodynamics Open-circuit subsonic wind tunnel for a wide range of investigations into aerodynamics Page 1 of 4 Works with Computer, chair and work table shown for photographic purposes only (not included) Screenshot

More information

Energy from wind and water extracted by Horizontal Axis Turbine

Energy from wind and water extracted by Horizontal Axis Turbine Energy from wind and water extracted by Horizontal Axis Turbine Wind turbines in complex terrain (NREL) Instream MHK turbines in complex bathymetry (VP East channel NewYork) Common features? 1) horizontal

More information

Wind-Induced Oscillations Parametric Wind Tunnel Test

Wind-Induced Oscillations Parametric Wind Tunnel Test National Aeronautics and Space Administration Wind-Induced Oscillations Parametric Wind Tunnel Test Sam Yunis, Donald Keller, Thomas Ivanco, Jennifer Pinkerton NASA Langley Presented at Spacecraft and

More information

The Aerodynamic Drag of Parafoils

The Aerodynamic Drag of Parafoils The Aerodynamic Drag of Parafoils A. C. Carruthers and A. Filippone The University of Manchester Manchester M60 1QD United Kingdom Introduction The parafoil is an aerodynamic decelerator that uses the

More information

Citation Journal of Thermal Science, 18(4),

Citation Journal of Thermal Science, 18(4), NAOSITE: Nagasaki University's Ac Title Author(s) Noise characteristics of centrifuga diffuser (Noise reduction by means leading tip) Murakami, Tengen; Ishida, Masahiro; Citation Journal of Thermal Science,

More information

AERODYNAMIC CHARACTERISTICS OF NACA 0012 AIRFOIL SECTION AT DIFFERENT ANGLES OF ATTACK

AERODYNAMIC CHARACTERISTICS OF NACA 0012 AIRFOIL SECTION AT DIFFERENT ANGLES OF ATTACK AERODYNAMIC CHARACTERISTICS OF NACA 0012 AIRFOIL SECTION AT DIFFERENT ANGLES OF ATTACK SUPREETH NARASIMHAMURTHY GRADUATE STUDENT 1327291 Table of Contents 1) Introduction...1 2) Methodology.3 3) Results...5

More information

APPLICATION OF RESEARCH RESULTS AT LM WIND POWER

APPLICATION OF RESEARCH RESULTS AT LM WIND POWER APPLICATION OF RESEARCH RESULTS AT LM WIND POWER Herning / March 27 / 2014 By Jesper Madsen Chief Engineer Aerodynamics and Acoustics AGENDA 1. EUDP Projects 1. DANAERO MW 2. Optimization of vortex generators

More information

Experimental and Theoretical Investigation for the Improvement of the Aerodynamic Characteristic of NACA 0012 airfoil

Experimental and Theoretical Investigation for the Improvement of the Aerodynamic Characteristic of NACA 0012 airfoil International Journal of Mining, Metallurgy & Mechanical Engineering (IJMMME) Volume 2, Issue 1 (214) ISSN 232 46 (Online) Experimental and Theoretical Investigation for the Improvement of the Aerodynamic

More information

Unsteady airfoil experiments

Unsteady airfoil experiments Unsteady airfoil experiments M.F. Platzer & K.D. Jones AeroHydro Research & Technology Associates, Pebble Beach, CA, USA. Abstract This paper describes experiments that elucidate the dynamic stall phenomenon

More information

Computation of Flow Behind Three Side-by-Side Cylinders of Unequal/Equal Spacing

Computation of Flow Behind Three Side-by-Side Cylinders of Unequal/Equal Spacing Computation of Flow Behind Three Side-by-Side Cylinders of Unequal/Equal Spacing H. K. Virahsawmy 1, L. Chen 2, I. R. MacGillivray 2, J. Tu 1 and Y. Zhou 3 1. School of Aerospace, Mechanical and Manufacturing

More information

Influence of the external dynamic wind pressure on the ventilation of double facades

Influence of the external dynamic wind pressure on the ventilation of double facades Influence of the external dynamic wind pressure on the ventilation of double facades Claudia Ziller & Bernd Döring Institute of steel construction, Aachen, Germany ABSTRACT: The ventilation rate in the

More information

FUTURE Flutter-Free Turbomachinery Blades

FUTURE Flutter-Free Turbomachinery Blades Aero Days 2011, Madrid. FUTURE Flutter-Free Turbomachinery Blades Torsten Fransson, KTH Damian Vogt, KTH 2011-03-31 1 A Typical Turbomachine RR Trent 1000 Picture courtesy of RR 2 What is it flutter? 3

More information

Single Phase Pressure Drop and Flow Distribution in Brazed Plate Heat Exchangers

Single Phase Pressure Drop and Flow Distribution in Brazed Plate Heat Exchangers Purdue University Purdue e-pubs International Refrigeration and Air Conditioning Conference School of Mechanical Engineering 2016 Single Phase Pressure Drop and Flow Distribution in Brazed Plate Heat Exchangers

More information

average length of the bluff body surface reattachment will decrease with blockage ratio increasing. Cherry's test results showed that 5% of the blocka

average length of the bluff body surface reattachment will decrease with blockage ratio increasing. Cherry's test results showed that 5% of the blocka The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2 6, 2012 Investigation on wind tunnel blockage effect of super high-rise building WANG

More information

Bending Vibration Analysis of Pipes and Shafts Arranged in Fluid Filled Tubular Spaces Using FEM

Bending Vibration Analysis of Pipes and Shafts Arranged in Fluid Filled Tubular Spaces Using FEM Bending Vibration Analysis of Pipes and Shafts Arranged in Fluid Filled Tubular Spaces Using FEM By Desta Milkessa Under the guidance of : Prof. Dr.Eng. Patrick Kaeding Dipl.-Ing. Michael Holtmann Developed

More information

EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM

EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM EXPERIMENTAL AND ANALYTICAL INVESTIGATION OF THE EFFECT OF BODY KIT USED WITH SALOON CARS IN BRUNEI DARUSSALAM M.G., Yazdani, H. Ullah, T. Aderis and R. Zainulariffin, Faculty of Engineering, Institut

More information

COMPARISONS OF COMPUTATIONAL FLUID DYNAMICS AND

COMPARISONS OF COMPUTATIONAL FLUID DYNAMICS AND The Seventh Asia-Pacific Conference on Wind Engineering, November 8-12, 2009, Taipei, Taiwan COMPARISONS OF COMPUTATIONAL FLUID DYNAMICS AND WIND TUNNEL EXPERIMENTS FOR PEDESTRIAN WIND ENVIRONMENTS Chin-Hsien

More information

Measurement and simulation of the flow field around a triangular lattice meteorological mast

Measurement and simulation of the flow field around a triangular lattice meteorological mast Measurement and simulation of the flow field around a triangular lattice meteorological mast Matthew Stickland 1, Thomas Scanlon 1, Sylvie Fabre 1, Andrew Oldroyd 2 and Detlef Kindler 3 1. Department of

More information

Italy Published online: 24 Sep 2014.

Italy Published online: 24 Sep 2014. This article was downloaded by: [Politecnico di Milano Bibl] On: 20 January 2015, At: 07:39 Publisher: Taylor & Francis Informa Ltd Registered in England and Wales Registered Number: 1072954 Registered

More information

NUMERICAL SIMULATION OF STATIC INTERFERENCE EFFECTS FOR SINGLE BUILDINGS GROUP

NUMERICAL SIMULATION OF STATIC INTERFERENCE EFFECTS FOR SINGLE BUILDINGS GROUP NUMERICAL SIMULATION OF STATIC INTERFERENCE EFFECTS FOR SINGLE BUILDINGS GROUP Xing-qian Peng, Chun-hui Zhang 2 and Chang-gui Qiao 2 Professor, College of Civil Engineering, Huaqiao University, Quanzhou,

More information

OTC Copyright 2003, Offshore Technology Conference

OTC Copyright 2003, Offshore Technology Conference OTC 54 Model Test Experience on Vortex Induced Vibrations of Truss Spars Radboud van Dijk, Maritime Research Institute Netherlands, Allan Magee, Technip Offshore, Inc., Steve Perryman, BP Americas, Inc.,

More information

AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE

AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE - 247 - AIRFLOW GENERATION IN A TUNNEL USING A SACCARDO VENTILATION SYSTEM AGAINST THE BUOYANCY EFFECT PRODUCED BY A FIRE J D Castro a, C W Pope a and R D Matthews b a Mott MacDonald Ltd, St Anne House,

More information

Computational Investigation of Airfoils with Miniature Trailing Edge Control Surfaces

Computational Investigation of Airfoils with Miniature Trailing Edge Control Surfaces AIAA-24-5 Computational Investigation of Airfoils with Miniature Trailing Edge Control Surfaces Hak-Tae Lee, Ilan M. Kroo Stanford University, Stanford, CA 9435 Abstract Miniature trailing edge effectors

More information

The Influence of Battle Damage on the Aerodynamic Characteristics of a Model of an Aircraft

The Influence of Battle Damage on the Aerodynamic Characteristics of a Model of an Aircraft Proceedings of the 26 WSEAS/IASME International Conference on Fluid Mechanics, Miami, Florida, USA, January 18-2, 26 (pp7-76) The Influence of Battle on the Aerodynamic Characteristics of a Model of an

More information

Control of surge and pitch motions of a rectangular floating body using internal sloshing phenomena. Minho Ha and *Cheolung Cheong 1)

Control of surge and pitch motions of a rectangular floating body using internal sloshing phenomena. Minho Ha and *Cheolung Cheong 1) Control of surge and pitch motions of a rectangular floating body using internal sloshing phenomena Minho Ha and *Cheolung Cheong 1) School of Mechanical Engineering, PNU, Busan 609-735, Korea 1) ccheong@pusan.ac.kr

More information

A NOVEL FLOATING OFFSHORE WIND TURBINE CONCEPT: NEW DEVELOPMENTS

A NOVEL FLOATING OFFSHORE WIND TURBINE CONCEPT: NEW DEVELOPMENTS A NOVEL FLOATING OFFSHORE WIND TURBINE CONCEPT: NEW DEVELOPMENTS L. Vita, U.S.Paulsen, T.F.Pedersen Risø-DTU Technical University of Denmark, Roskilde, Denmark luca.vita@risoe.dk Abstract: A novel concept

More information