# Basis of Structural Design

Save this PDF as:

Size: px
Start display at page:

## Transcription

2 Wind loading: normative references Normative references EN : Eurocode 1: Actions on structures - Part 1-4: General actions - Wind actions CR 1-1-4/2012: Cod de proiectare. Evaluarea acţiunii vântului asupra construcţiilor. Wind action is classified as variable fixed actions according to EN 1990

3 Nature of wind loading Wind represents masses of air moving mainly horizontally (parallel to the ground) from areas of high pressure to ones of low pressure Wind generates pressures on external (and also internal) surfaces of structures The main effect of wind is a horizontal loading on buildings (especially high-rise) The effect of the wind on the structure (i.e. the response of the structure), depends on the size, shape and dynamic properties of the structure.

4 Basic value of mean wind velocity The reference value of the wind velocity, v b, is the characteristic 10 minutes mean wind velocity, irrespective of wind direction and time of year, at 10 m above ground level in open country terrain with low vegetation such as grass and isolated obstacles with separations of at least 20 obstacle heights. Reference values of wind velocity are determined for annual probabilities of exceedence of 0.02, which is equivalent to a mean return period of 50 years. For design purposes, basic values of wind velocity are obtained from maps and tables given in codes (CR /2012).

5 Reference wind pressure Reference wind pressure q b is the wind pressure corresponding to the reference value of the wind velocity v b q b 1 v 2 2 b where: is the air density, which depends on altitude, temperature, latitude and season. The recommended value for design is 1.25 kg/m 3 For design purposes, reference wind pressure are obtained from maps and tables given in codes (CR / 2012).

6 Reference wind pressure

7 Mean wind velocity: gradient height The mean wind velocity at great heights above the ground is constant and it is called the gradient wind speed. Near the ground the mean wind velocity is decreasing much due to frictional forces caused by the terrain, being equal with zero at the ground level. There is a boundary layer within which the wind speed varies from zero to the gradient wind speed (mean wind velocity increases with height).

8 Mean wind velocity: gradient height The thickness of the boundary layer (gradient height) depends on the ground roughness. Larger the roughness, larger the gradient height.

9 Mean wind velocity: terrain categories

10 Mean wind velocity: terrain categories

11 Mean wind velocity: terrain categories Terrain roughness is described aerodynamically by the roughness length, z 0, expressed in meters. It represents a measure of the dimensions of eddies of turbulent wind at the ground surface.

12 Mean wind velocity: variation with height The mean wind velocity profile within the atmospheric boundary layer can be described by a logarithmic law: v z c z v m r b c r z z k r z ln for z z z z c r z z 0 min max 0 z z min min where: c r (z) is a roughness factor z - height above ground z 0 roughness length

13 Mean wind velocity: variation with height The terrain factor k r (z 0 ) is given by the relationship: k r 0,07 z0 z 0 0,189 0,05

14 Mean wind pressure: variation with height The roughness factor c r (z) is used to describe the variation of wind pressure with height q z c z q 2 m r b

15 Wind turbulence Wind velocity varies with time as shown in the figure below. This variation with respect to the mean wind velocity is called turbulence and is generated by the eddies caused by the wind blowing over obstacles

16 Wind turbulence The turbulence intensity I(z) at height z is defined as the standard deviation of the turbulence divided by the mean wind velocity. I v z v v z m The turbulence intensity I(z) at height z can be expressed as: I v z z 2.5ln z I v z z 0 min for z z z 200m min max for z z min

17 Wind turbulence Wind turbulence decreases with height above ground

18 Wind turbulence: gust factor The gust factor c pq (z) is the ratio between the peak pressure (due to wind turbulence) and mean pressure (due to mean wind velocity) The gust factor c pq (z) can be determined as: c z 1 2g I z 1 7 I z pq v v where: g = 3.5 is the amplitude factor I v (z) is the turbulence intensity at height z

19 Wind turbulence: gust factor

20 Wind pressure at height z Wind pressure at height z above ground can be obtained by considering the effects of mean wind velocity, wind turbulence, and topography on the reference pressure q b (at the ground level) Mean wind velocity increases with height above ground. The effect of mean wind velocity on wind pressure profile is accounted through the roughness factor c r (z) Wind turbulence decreases with height above ground. The effect of wind turbulence on wind pressure at height z is accounted through the gust factor c pq (z) Isolated hills and other local topographical accidents can affect the mean wind velocity. In design this effect is accounted through the orography factor c o. It need not be considered when the slope is less than 5% (c o =1.0).

21 Effect of topography Wind pressure at height z

22 Wind pressure at height z can be obtained as: q z c z q p e b The product between the gust factor, the roughness factor and the topographical factor is called the exposure factor, and is denoted by c e (z): c z c c z c z 2 2 e o r pq Wind pressure at height z

23 Wind pressure at height z c z c c z c z 2 2 e o r pq

24 Nature of wind loading Wind actions act directly as pressures on the external surfaces of enclosed structures and, because of porosity of the external surface, also act indirectly on the internal surfaces. They may also act directly on the internal surface of open structures. Pressures act on areas of the surface resulting in forces normal to the surface of the structure or of individual cladding components. Additionally, when large areas of structures are swept by the wind, friction forces acting tangentially to the surface may be significant. The wind action is represented by a simplified set of pressures or forces whose effects are equivalent to the extreme effects of the turbulent wind.

25 Wind effects on structures Wind effects on structures can be classified as follows: static or quasistatic response turbulence induced vibrations vortex induced vibrations galloping flutter response due to interference of nearby structures

26 Wind effects on structures Most buildings are not streamlined, and are called bluff bodies in aerodynamics. drag force, in the direction of the flow F D = C D q lift force, perpendicular to flow direction torsion moment For bluff bodies, wind flow separates and causes the formation of the so-called "wake" pressure on the windward side suction on the leeward side suction/pressure on lateral surfaces

27 Wind pressure on surfaces Wind pressure w(z) on rigid exterior and interior surfaces of the structure at height z above ground are obtained as: w c q z w c q z e Iw pe p e where: Iw the importance factor q p (z e ) peak wind pressure at level z e z e reference height for external pressure. c p aerodynamic pressure coefficient (c pe for exterior surfaces; c pi for internal surfaces) Pressures are considered positive (+) Suction is considered negative (-) i Iw pi p i The total pressure on a structural element is obtained as the algebraic sum of pressures on one side and suction on the other side

28 Wind pressure on surfaces Wind pressure w(z) on rigid exterior and interior surfaces of the structure at height z above ground are obtained as: w e Iw cpe qp z e w c q z i Iw pi p i

29 Aerodynamic pressure coefficients Aerodynamic pressure coefficients depend on: geometry of the structure/element size of the structure/element terrain roughness wind direction with respect to the structure Reynolds number etc.

30 Pressure coefficients: loaded area Aerodynamic pressure coefficients c pe for buildings and parts of buildings depend on the size of the loaded area A, which is the area of the structure, that produces the wind action in the section to be calculated Values for c pe,1 are intended for the design of small elements and fixings with an area per element of 1 m 2 or less such as cladding elements and roofing elements. Values for c pe,10 may be used for the design of the overall load bearing structure of buildings. Due to non-uniform action of wind, peak pressure on a small area is higher than the peak overall pressure on a large area (for which some portions are loaded less)

31 Press. coeff.: vertical walls of rect. plan buildings The reference heights, z e, for rectangular plan buildings depend on the aspect ratio h/b and are always the upper heights of the different parts of the walls Reference heights are used to compute the exposure factor c e (z) Three cases: A building, whose height h is less than b should be considered to be one part.

32 Press. coeff.: vertical walls of rect. plan buildings A building, whose height h is greater than b, but less than 2b, may be considered to be two parts, comprising: a lower part extending upwards from the ground by a height equal to b and an upper part consisting of the remainder.

33 Press. coeff.: vertical walls of rect. plan buildings A building, whose height h is greater than 2b may be considered to be in multiple parts, comprising: a lower part extending upwards from the ground by a height equal to b; an upper part extending downwards from the top by a height equal to b and a middle region, between the upper and lower parts, which may be divided into horizontal strips with a height h strip (max h strip = b)

34 Press. coeff.: vertical walls of rect. plan buildings Depending on geometry and position with respect to wind direction, different regions of vertical walls are assigned different names, with corresponding values of pressure coefficients c p

35 Press. coeff.: vertical walls of rect. plan buildings Depending on geometry and position with respect to wind direction, different regions of vertical walls are assigned different names, with corresponding values of pressure coefficients c p

36 Pressure coefficients Similar procedure are specified in the code for roofs of buildings (of different geometry), canopies, isolated vertical walls, fences etc.

37 Wind forces method For structures like signboards, lattice structures and scaffoldings, flags, etc. wind actions is modelled as a resultant force F c c q z A w Iw d f p e ref where: Iw the importance factor q p (z e ) peak wind pressure at level z e z e reference height for external pressure. c f - wind force coefficient c d - dynamic response coefficient A ref - reference area perpendicular on wind direction

41 Other loads: wave loading For offshore structures in deep waters, wave loads can be particularly severe. The loads arise due to movement of water associated with wave action. These movements can be described mathematically to relate forces to physical wave characteristics such as height and wavelength. The treatment is therefore similar to wind loads in that these physical characteristics are predicted and corresponding forces on the particular structural arrangement then calculated. These calculation procedures are, however, very complicated and must realistically be performed on a computer.

42 Other loads: temperature effects Exposed structures such as bridges may be subject to significant temperature variation which must be taken into account in the design. If it is not provided for in terms of allowing for expansion, significant forces may develop and must be included in the design calculations. In addition, differential temperatures, e.g. between the concrete deck and steel girders of a composite bridge, can induce a stress distribution which must be considered by the designer.

43 Other loads: retained material Structures for retaining and containing material (granular or liquid) will be subject to a lateral pressure. For liquids it is simply the hydrostatic pressure. For granular material a similar approach can be adopted, but with a reduction in pressure depending on the ability of the material to maintain a stable slope - this is the Rankine approach. Ponding of water on flat roofs should be avoided by ensuring adequate falls (1:60 or more) to gutters.

44 Other loads: seismic loads Seismic actions on structures are due to strong ground motion. They are a function of the ground motion itself and of the dynamic characteristics of the structure. Strong ground motion can be measured by one of its parameters, the peak ground acceleration being the parameter most usually adopted for engineering purposes.

45 Other loads: accidental loads Accidental actions may occur as a result of accidental situations. The situations include fire, impact or explosion. It is very difficult to quantify these effects. In many cases it may be preferable to avoid the problem, for instance by providing crash barriers to avoid collision from vehicles or roof vents to dissipate pressures from explosions. Where structures such as crash barriers for vehicles and crowds must be designed for 'impact' the loading is treated as an equivalent static load.

### CIVL473 Fundamentals of Steel Design

Loading for most of the structures are obtained from the relevant British Standards, the manufacturers data and similar sources. CIVL473 Fundamentals of Steel Design CHAPTER 2 Loading and Load Combinations

### Available online at ScienceDirect. Procedia Engineering 161 (2016 )

Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 161 (216 ) 1845 1851 World Multidisciplinary Civil Engineering-Architecture-Urban Planning Symposium 216, WMCAUS 216 Experimental

### ESCI 343 Atmospheric Dynamics II Lesson 10 - Topographic Waves

ESCI 343 Atmospheric Dynamics II Lesson 10 - Topographic Waves Reference: An Introduction to Dynamic Meteorology (3 rd edition), J.R. Holton Reading: Holton, Section 7.4. STATIONARY WAVES Waves will appear

### Wind tunnel tests of a non-typical stadium roof

Wind tunnel tests of a non-typical stadium roof G. Bosak 1, A. Flaga 1, R. Kłaput 1 and Ł. Flaga 1 1 Wind Engineering Laboratory, Cracow University of Technology, 31-864 Cracow, Poland. liwpk@windlab.pl

### STABILITY OF MULTIHULLS Author: Jean Sans

STABILITY OF MULTIHULLS Author: Jean Sans (Translation of a paper dated 10/05/2006 by Simon Forbes) Introduction: The capsize of Multihulls requires a more exhaustive analysis than monohulls, even those

### Wind tunnel test and numerical simulation of wind pressure on a high-rise building

Journal of Chongqing University (English Edition) [ISSN 1671-8224] Vol. 9 No. 1 March 2010 Article ID: 1671-8224(2010)01-0047-07 To cite this article: AL ZOUBI Feras, LI Zheng-liang, WEI Qi-ke, SUN Yi.

### 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,

### Chapter 3 PRESSURE AND FLUID STATICS

Fluid Mechanics: Fundamentals and Applications, 2nd Edition Yunus A. Cengel, John M. Cimbala McGraw-Hill, 2010 Chapter 3 PRESSURE AND FLUID STATICS Lecture slides by Hasan Hacışevki Copyright The McGraw-Hill

### Wind action on small sky observatory ScopeDome

Wind action on small sky observatory ScopeDome A.Flaga a, G. Bosak a, Ł. Flaga b, G. Kimbar a, M. Florek a a Wind Engineering Laboratory, Cracow University of Technology, Cracow, Poland, LIWPK@windlab.pl

### 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

### 5. A bead slides on a curved wire, starting from rest at point A in the figure below. If the wire is frictionless, find each of the following.

Name: Work and Energy Problems Date: 1. A 2150 kg car moves down a level highway under the actions of two forces: a 1010 N forward force exerted on the drive wheels by the road and a 960 N resistive force.

### PHASE 1 WIND STUDIES REPORT

PHASE 1 WIND STUDIES REPORT ENVIRONMENTAL STUDIES AND PRELIMINARY DESIGN FOR A SUICIDE DETERRENT SYSTEM Contract 2006-B-17 24 MAY 2007 Golden Gate Bridge Highway and Transportation District Introduction

### APPLICATION OF COMPUTATIONAL FLUID DYNAMICS (CFD) IN WIND ANALYSIS OF TALL BUILDINGS. Damith Mohotti, Priyan Mendis, Tuan Ngo

APPLICATION OF COMPUTATIONAL FLUID DYNAMICS (CFD) IN WIND ANALYSIS OF TALL BUILDINGS Damith Mohotti, Priyan Mendis, Tuan Ngo Department of Infrastructures Engineering, The University of Melbourne, Victoria,

### FINAL REPORT. Wind Assessment for: NEW OFFICE BUILDING AT ESSENDON FIELDS Essendon, Victoria, Australia

FINAL REPORT Wind Assessment for: NEW OFFICE BUILDING AT ESSENDON FIELDS Essendon, Victoria, Australia Prepared for: Essendon Fields Pty Ltd Essendon Fields House Level 2, 7 English Street Essendon Fields

### Outline. Wind Turbine Siting. Roughness. Wind Farm Design 4/7/2015

Wind Turbine Siting Andrew Kusiak 2139 Seamans Center Iowa City, Iowa 52242-1527 andrew-kusiak@uiowa.edu Tel: 319-335-5934 Fax: 319-335-5669 http://www.icaen.uiowa.edu/~ankusiak Terrain roughness Escarpments

### Fire and Safety for Offshore drilling and production Ajey Walavalkar ANSYS Inc.

Fire and Safety for Offshore drilling and production Ajey Walavalkar ANSYS Inc. 1 ANSYS, Inc. September 12, Fire and safety related applications Gas Dispersion and Ventilation Formation of combustible

### Scales of Atmospheric Motion Scale Length Scale (m) Time Scale (sec) Systems/Importance Molecular (neglected)

Supplement Wind, Fetch and Waves Scales of Atmospheric Motion Scale Length Scale (m) Time Scale (sec) Systems/Importance Molecular 10-7 - 10-2 10-1 (neglected) Coriolis not important Turbulent 10-2 10

### 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,

### Sea and Land Breezes METR 4433, Mesoscale Meteorology Spring 2006 (some of the material in this section came from ZMAG)

Sea and Land Breezes METR 4433, Mesoscale Meteorology Spring 2006 (some of the material in this section came from ZMAG) 1 Definitions: The sea breeze is a local, thermally direct circulation arising from

### RESEARCH ON THE WIND LOAD PARAMETERS AND THE WIND FENCES BEHAVIOR FOR WIND FENCES OF RAILWAY BRIDGE

RESEARCH ON THE WIND LOAD PARAMETERS AND THE WIND FENCES BEHAVIOR FOR WIND FENCES OF RAILWAY BRIDGE Shi-xiong Zheng Professor, School of Civil Engineering, Southwest Jiaotong University Chengdu Sichuan

### Principles of glider flight

Principles of glider flight [ Lecture 1: Lift, drag & glide performance ] Richard Lancaster Email: Richard@RJPLancaster.net Twitter: @RJPLancaster ASK-21 illustrations Copyright 1983 Alexander Schleicher

### Determination of the wind pressure distribution on the facade of the triangularly shaped high-rise building structure

Determination of the wind pressure distribution on the facade of the triangularly shaped high-rise building structure Norbert Jendzelovsky 1,*, Roland Antal 1 and Lenka Konecna 1 1 STU in Bratislava, Faculty

### 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

### Standard atmosphere Typical height (m) Pressure (mb)

Standard atmosphere Pressure (mb) Typical height (ft) Typical height (m) 1013.25 0 0 1000 370 110 850 4780 1460 700 9880 3010 500 18280 5570 300 30050 9160 Whiteman 2000 Pressure decreases exponentially

### 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

### Energy Output. Outline. Characterizing Wind Variability. Characterizing Wind Variability 3/7/2015. for Wind Power Management

Energy Output for Wind Power Management Spring 215 Variability in wind Distribution plotting Mean power of the wind Betz' law Power density Power curves The power coefficient Calculator guide The power

### Performance Standards for Non-Turf Cricket Pitches Intended for Outdoor Use [TS6] ecb.co.uk

Performance Standards for Non-Turf Cricket Pitches Intended for Outdoor Use [TS6] ecb.co.uk 01 Introduction and Scope This Standard describes the requirements for non-turf cricket pitch systems intended

### Module 15 : Grit Chamber. Lecture 20 : Grit Chamber

1 P age Module 15 : Grit Chamber Lecture 20 : Grit Chamber 2 P age 15.6 Square Grit Chamber The horizontal flow rectangular grit chamber faces the problem of sedimentation of organic matter along with

### Predicting and Controlling Bubble Clogging in Bioreactor for Bone Tissue Engineering

Predicting and Controlling Bubble Clogging in Bioreactor for Bone Tissue Engineering Marina Campolo, Dafne Molin, Alfredo Soldati Centro Interdipartimentale di Fluidodinamica e Idraulica and Department

### APPLICATION OF PUSHOVER ANALYSIS ON EARTHQUAKE RESPONSE PREDICATION OF COMPLEX LARGE-SPAN STEEL STRUCTURES

APPLICATION OF PUSHOVER ANALYSIS ON EARTHQUAKE RESPONSE PREDICATION OF COMPLEX LARGE-SPAN STEEL STRUCTURES J.R. Qian 1 W.J. Zhang 2 and X.D. Ji 3 1 Professor, 3 Postgraduate Student, Key Laboratory for

### Wind Loads on Low-Rise Building Models with Different Roof Configurations

Wind Loads on Low-Rise Building Models with Different Roof Configurations Deepak Prasad, Tuputa Uliate, and M. Rafiuddin Ahmed School of Engineering and Physics, Faculty of Science and Technology, The

### Agood tennis player knows instinctively how hard to hit a ball and at what angle to get the ball over the. Ball Trajectories

42 Ball Trajectories Factors Influencing the Flight of the Ball Nathalie Tauziat, France By Rod Cross Introduction Agood tennis player knows instinctively how hard to hit a ball and at what angle to get

### Lift for a Finite Wing. all real wings are finite in span (airfoils are considered as infinite in the span)

Lift for a Finite Wing all real wings are finite in span (airfoils are considered as infinite in the span) The lift coefficient differs from that of an airfoil because there are strong vortices produced

### EDEXCEL NATIONALS UNIT 6 MECHANICAL PRINCIPLES and APPLICATIONS. ASSIGNMENT No. 4

EDEXCEL NATIONALS UNIT 6 MECHANICAL PRINCIPLES and APPLICATIONS ASSIGNMENT No. 4 NAME: I agree to the assessment as contained in this assignment. I confirm that the work submitted is my own work. Signature

### Undertow - Zonation of Flow in Broken Wave Bores

Nearshore Circulation Undertow and Rip Cells Undertow - Zonation of Flow in Broken Wave Bores In the wave breaking process, the landward transfer of water, associated with bore and surface roller decay

### Job Sheet 1 Blade Aerodynamics

Job Sheet 1 Blade Aerodynamics The rotor is the most important part of a wind turbine. It is through the rotor that the energy of the wind is converted into mechanical energy, which turns the main shaft

### THE INFLUENCE OF THE NOSE SHAPE OF HIGH SPEED TRAINS ON THE AERODYNAMIC COEFFICIENTS

THE INFLUENCE OF THE NOSE SHAPE OF HIGH SPEED TRAINS ON THE AERODYNAMIC COEFFICIENTS Heine Ch. and Matschke G. Deutsche Bahn AG, Research and Technology Centre Voelckerstrasse 5, D-80939 Munich, Germany

### Figure 1 Figure 1 shows the involved forces that must be taken into consideration for rudder design. Among the most widely known profiles, the most su

THE RUDDER starting from the requirements supplied by the customer, the designer must obtain the rudder's characteristics that satisfy such requirements. Subsequently, from such characteristics he must

### Available online at ScienceDirect. Procedia Engineering 126 (2015 )

Available online at www.sciencedirect.com ScienceDirect Procedia Engineering 126 (2015 ) 542 548 7th International Conference on Fluid Mechanics, ICFM7 Terrain effects on characteristics of surface wind

### Stefan Emeis

The Physics of Wind Park Optimization Stefan Emeis stefan.emeis@kit.edu INSTITUTE OF METEOROLOGY AND CLIMATE RESEARCH, Photo: Vattenfall/C. Steiness KIT University of the State of Baden-Wuerttemberg and

### PRE-TEST Module 2 The Principles of Flight Units /60 points

PRE-TEST Module 2 The Principles of Flight Units 1-2-3.../60 points 1 Answer the following questions. (20 p.) moving the plane (4) upward / forward. Opposed to that is 1. What are the names of the four

### Atmospheric Stability/Skew-T Diagrams. Fall 2016

Atmospheric Stability/Skew-T Diagrams Fall 2016 Air Parcel Consider a parcel of infinitesimal dimensions that is: Thermally isolated from the environment so that its temperature changes adiabatically as

### Wind Energy Technology. What works & what doesn t

Wind Energy Technology What works & what doesn t Orientation Turbines can be categorized into two overarching classes based on the orientation of the rotor Vertical Axis Horizontal Axis Vertical Axis Turbines

### Chapter 14. Vibrations and Waves

Chapter 14 Vibrations and Waves Chapter 14 Vibrations and Waves In this chapter you will: Examine vibrational motion and learn how it relates to waves. Determine how waves transfer energy. Describe wave

### THE CURVE OF THE CRICKET BALL SWING AND REVERSE SWING

Parabola Volume 32, Issue 2 (1996) THE CURVE OF THE CRICKET BALL SWING AND REVERSE SWING Frank Reid 1 It is a well known fact in cricket that the new ball when bowled by a fast bowler will often swing

### Modelling and Simulation of Environmental Disturbances

Modelling and Simulation of Environmental Disturbances (Module 5) Dr Tristan Perez Centre for Complex Dynamic Systems and Control (CDSC) Prof. Thor I Fossen Department of Engineering Cybernetics 18/09/2007

### Centre for Offshore Renewable Energy Engineering, School of Energy, Environment and Agrifood, Cranfield University, Cranfield, MK43 0AL, UK 2

Fluid Structure Interaction Modelling of A Novel 10MW Vertical-Axis Wind Turbine Rotor Based on Computational Fluid Dynamics and Finite Element Analysis Lin Wang 1*, Athanasios Kolios 1, Pierre-Luc Delafin

### 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

### The Wind Resource: Prospecting for Good Sites

The Wind Resource: Prospecting for Good Sites Bruce Bailey, President AWS Truewind, LLC 255 Fuller Road Albany, NY 12203 bbailey@awstruewind.com Talk Topics Causes of Wind Resource Impacts on Project Viability

### Wind resource assessment over a complex terrain covered by forest using CFD simulations of neutral atmospheric boundary layer with OpenFOAM

Wind resource assessment over a complex terrain covered by forest using CFD simulations of neutral atmospheric boundary layer with OpenFOAM Nikolaos Stergiannis nstergiannis.com nikolaos.stergiannis@vub.ac.be

### WAVE LOAD ACTING ON HORIZONTAL PLATE DUE TO BORE

Proceedings of the 6 th International Conference on the Application of Physical Modelling in Coastal and Port Engineering and Science (Coastlab16) Ottawa, Canada, May 10-13, 2016 Copyright : Creative Commons

### IS: 875(Part3): Wind Loads on Buildings and Structures -Proposed Draft & Commentary

Document No. :: IITK-GSDMA-Wind02-V5.0 :: IITK-GSDMA-Wind04-V3.0 Final Report :: B - Wind Codes IITK-GSDMA Project on Building Codes IS: 875(Part3): Wind Loads on Buildings and Structures -Proposed Draft

### Unsteady Wave-Driven Circulation Cells Relevant to Rip Currents and Coastal Engineering

Unsteady Wave-Driven Circulation Cells Relevant to Rip Currents and Coastal Engineering Andrew Kennedy Dept of Civil and Coastal Engineering 365 Weil Hall University of Florida Gainesville, FL 32611 phone:

### . In an elevator accelerating upward (A) both the elevator accelerating upward (B) the first is equations are valid

IIT JEE Achiever 2014 Ist Year Physics-2: Worksheet-1 Date: 2014-06-26 Hydrostatics 1. A liquid can easily change its shape but a solid cannot because (A) the density of a liquid is smaller than that of

### Conditions for Offshore Wind Energy Use

Carl von Ossietzky Universität Oldenburg Institute of Physics Energy Meteorology Group Detlev Heinemann Conditions for Offshore Wind Energy Use Detlev Heinemann ForWind Carl von Ossietzky Universität Oldenburg

### 1. A tendency to roll or heel when turning (a known and typically constant disturbance) 2. Motion induced by surface waves of certain frequencies.

Department of Mechanical Engineering Massachusetts Institute of Technology 2.14 Analysis and Design of Feedback Control Systems Fall 2004 October 21, 2004 Case Study on Ship Roll Control Problem Statement:

### Steady and moving high-speed train crosswind simulations. Comparison with wind-tunnel tests.

Steady and moving high-speed train crosswind simulations. Comparison with wind-tunnel tests. Federico Cheli, Daniele Rocchi, Paolo Schito, Gisella Tomasini Dipartimento di Meccanica del Politecnico di

Wind Adaptive Building Envelope For Reducing Wind Effect on High-rise Puttakhun Vongsingha 4314395 P2 Report 23/01/2015 ii Wind Adaptive Building Envelope For Reducing Wind Effect on High-rise Table of

### Research on Goods and the Ship Interaction Based on ADAMS

Research on Goods and the Ship Interaction Based on ADAMS Fangzhen Song, Yanshi He and Haining Liu School of Mechanical Engineering, University of Jinan, Jinan, 250022, China Abstract. The equivalent method

### Mechanical Waves. Chapter 15. PowerPoint Lectures for University Physics, Thirteenth Edition Hugh D. Young and Roger A. Freedman

Chapter 15 Mechanical Waves PowerPoint Lectures for University Physics, Thirteenth Edition Hugh D. Young and Roger A. Freedman Lectures by Wayne Anderson Goals for Chapter 15 To study the properties and

### Similarly to elastic waves, sound and other propagated waves are graphically shown by the graph:

Phys 300/301 Physics: Algebra/Trig Eugene Hecht, 3e. Prepared 01/24/06 11.0 Waves & Sounds There are two fundamental waves of transporting energy and momentum: particles and waves. While they seem opposites,

### Clarification of Behavior of Huge Tsunami Action on Bridges - Hydraulic Model Experiment and Simulation Technology -

Clarification of Behavior of Huge Tsunami Action on Bridges - Hydraulic Model Experiment and Simulation Technology - 21 TOSHIMITSU SUZUKI *1 RIKUMA SHIJO *2 KAORU YOKOYAMA *3 SYUNICHI IKESUE *4 HIROFUMI

### High Speed Rail Tunnel Aerodynamics: Transient pressure and loadings on fixed tunnel equipment

High Speed Rail Tunnel Aerodynamics: Transient pressure and loadings on fixed tunnel equipment Mohammad Tabarra & Richard Sturt Arup, UK Summary: Trains entering tunnels at high speeds can generate highly

### BASE STATION ANTENNAS RELIABLE WIND LOAD CALCULATION

White Paper BASE STATION ANTENNAS RELIABLE WIND LOAD CALCULATION CONTENTS Abstract The importance of the wind load Methods of determining the wind load Determining the wind load The principle of the wind

### RESOLUTION MSC.141(76) (adopted on 5 December 2002) REVISED MODEL TEST METHOD UNDER RESOLUTION 14 OF THE 1995 SOLAS CONFERENCE

MSC 76/23/Add.1 RESOLUTION MSC.141(76) THE MARITIME SAFETY COMMITTEE, RECALLING Article 38(c) of the Convention on the International Maritime Organization concerning the functions of the Committee, RECALLING

### Figure 1. Outer dimensions of the model trucks.

1 Standardisation of test method for salt spreader: Air flow experiments Report 3: Simulations of airflow patterns by Jan S. Strøm, Consultant Aarhus University, Engineering Centre Bygholm, Test and Development

### WIND SHEAR, ROUGHNESS CLASSES AND TURBINE ENERGY PRODUCTION

WIND SHEAR, ROUGHNESS CLASSES AND TURBINE ENERGY PRODUCTION M. Ragheb /18/17 INTRODUCTION At a height of about 1 kilometer the wind is barely affected by the surface of the Earth. In the lower atmospheric

### WIND LOADS / MOORING & FISH TAILING. Arjen Koop, Senior Project Manager Offshore Rogier Eggers, Project Manager Ships

WIND LOADS / MOORING & FISH TAILING Arjen Koop, Senior Project Manager Offshore Rogier Eggers, Project Manager Ships OVERVIEW Wind Loads Wind shielding Fish tailing? 2 WIND LOADS FOR OFFSHORE MARS TLP

### a high-rise (78 m) building in the city of Antwerp. CFD simulations are performed for the building with and without second-skin facade concept impleme

The Seventh International Colloquium on Bluff Body Aerodynamics and Applications (BBAA7) Shanghai, China; September 2-6, 2012 CFD analysis of wind comfort on high-rise building balconies: validation and

### VISUAL AIDS FOR DENOTING OBSTACLES

CHAPTER 6. VISUAL AIDS FOR DENOTING OBSTACLES 6.1 Objects to be marked and/or lighted Note. The marking and/or lighting of obstacles is intended to reduce hazards to aircraft by indicating the presence

### Section 1 Types of Waves

CHAPTER OUTLINE Section 1 Types of Waves Key Idea questions > What does a wave carry? > How are waves generated? > What is the difference between a transverse wave and a longitudinal wave? > How do the

### Effects of seam and surface texture on tennis balls aerodynamics

Available online at www.sciencedirect.com Procedia Engineering 34 (2012 ) 140 145 9 th Conference of the International Sports Engineering Association (ISEA) Effects of seam and surface texture on tennis

### THE 21 st CHESAPEAKE SAILING YACHT SYMPOSIUM ANNAPOLIS, MARYLAND, MARCH 2013

THE 21 st CHESAPEAKE SAILING YACHT SYMPOSIUM ANNAPOLIS, MARYLAND, MARCH 2013 A wind tunnel study of the interaction between two sailing yachts P.J. Richards, D.J. Le Pelley, D. Jowett, J. Little, O. Detlefsen

### Gravity waves and bores. Material kindly provided by Dr. Steven Koch GSD NOAA (Boulder, CO)

Gravity waves and bores Material kindly provided by Dr. Steven Koch GSD NOAA (Boulder, CO) Presented at Iowa State University 11 April 2005 What is a gravity wave? An oscillation caused by the displacement

### Modelling atmospheric stability with CFD: The importance of tall profiles

ENERGY Modelling atmospheric stability with CFD: The importance of tall profiles VindKraftNet Seminar on Profiles Jean-François Corbett, Global Head of CFD Service 1 SAFER, SMARTER, GREENER DNV GL CFD

### Chapter 11 Waves. Waves transport energy without transporting matter. The intensity is the average power per unit area. It is measured in W/m 2.

Chapter 11 Waves Energy can be transported by particles or waves A wave is characterized as some sort of disturbance that travels away from a source. The key difference between particles and waves is a

### 4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES Student Notes

4.4 WAVE CHARACTERISTICS 4.5 WAVE PROPERTIES Student Notes I. DIFFERENT TYPES OF WAVES A. TRANSVERSE AND LONGITUDINAL WAVES B. WAVE PULSES AND TRAVELLING WAVES C. SOUND AND WATER WAVES II. DEFINING TERMS

### and its weight (in newtons) when located on a planet with an acceleration of gravity equal to 4.0 ft/s 2.

1.26. A certain object weighs 300 N at the earth's surface. Determine the mass of the object (in kilograms) and its weight (in newtons) when located on a planet with an acceleration of gravity equal to

### Queue analysis for the toll station of the Öresund fixed link. Pontus Matstoms *

Queue analysis for the toll station of the Öresund fixed link Pontus Matstoms * Abstract A new simulation model for queue and capacity analysis of a toll station is presented. The model and its software

### Design a grit chamber for population with water consumption of 135 LPCD.

1 Example:1 Design a grit chamber for population 50000 with water consumption of 135 LPCD. Solution Average quantity of sewage, considering sewage generation 80% of water supply, is = 135 x 50000 x 0.8

### Georgian University GEOMEDI. Abstract. In this article we perform theoretical analysis of long jumps with the purpose to find

On the t Influence of Air Resistance and Wind during Long Jump Egoyan A. E. ( alex1cen@yahoo.com ), Khipashvili I. A. Georgian University GEOMEDI Abstract. In this article we perform theoretical analysis

### Sound scattering by hydrodynamic wakes of sea animals

ICES Journal of Marine Science, 53: 377 381. 1996 Sound scattering by hydrodynamic wakes of sea animals Dmitry A. Selivanovsky and Alexander B. Ezersky Selivanovsky, D. A. and Ezersky, A. B. 1996. Sound

### U S F O S B u o y a n c y And Hydrodynamic M a s s

1 U S F O S B u o y a n c y And Hydrodynamic M a s s 2 CONTENTS: 1 INTRODUCTION... 3 2 ACCURACY LEVELS... 3 2.1 LEVEL-0... 3 2.2 LEVEL-1... 3 2.3 PANEL MODEL... 3 3 EX 1. SINGLE PIPE. NON FLOODED... 4

### Akasison Flow phenomena of a siphonic roof outlet

Akasison Flow phenomena of a siphonic roof outlet Ir. Marc Buitenhuis MTD Hydraulic research engineer Akatherm BV, Panningen, The Netherlands 06-01-2011 Abstract So far the investigations on siphonic roof

### Wind loads investigations of HAWT with wind tunnel tests and site measurements

loads investigations of HAWT with wind tunnel tests and site measurements Shigeto HIRAI, Senior Researcher, Nagasaki R&D Center, Technical Headquarters, MITSUBISHI HEAVY INDSUTRIES, LTD, Fukahori, Nagasaki,

### Dynamic Stability of Ships in Waves

Gourlay, T.P. & Lilienthal, T. 2002 Dynamic stability of ships in waves. Proc. Pacific 2002 International Maritime Conference, Sydney, Jan 2002. ABSTRACT Dynamic Stability of Ships in Waves Tim Gourlay

### Jet Propulsion. Lecture-17. Ujjwal K Saha, Ph. D. Department of Mechanical Engineering Indian Institute of Technology Guwahati

Lecture-17 Prepared under QIP-CD Cell Project Jet Propulsion Ujjwal K Saha, Ph. D. Department of Mechanical Engineering Indian Institute of Technology Guwahati 1 Lift: is used to support the weight of

ADVANCES IN AERODYNAMICS OF WIND TURBINE BLADES Herning / October 3 / 2017 By Jesper Madsen Chief Engineer, Aerodynamics & Acoustics WIND ENERGY DENMARK Annual Event 2017 Agenda 1. Aerodynamic design and

### Aerofoil Profile Analysis and Design Optimisation

Journal of Aerospace Engineering and Technology Volume 3, Issue 2, ISSN: 2231-038X Aerofoil Profile Analysis and Design Optimisation Kondapalli Siva Prasad*, Vommi Krishna, B.B. Ashok Kumar Department

### Applications of Bernoulli s principle. Principle states that areas with faster moving fluids will experience less pressure

Applications of Bernoulli s principle Principle states that areas with faster moving fluids will experience less pressure Artery o When blood flows through narrower regions of arteries, the speed increases

### Attitude Instrument Flying and Aerodynamics

Attitude Instrument Flying and Aerodynamics 2.1 TURNS 1. An airplane requires a sideward force to make it turn. a. When the airplane is banked, lift (which acts perpendicular to the wingspan) acts not

### Chapter 2 Meteorology and Oceanography

PART II ACTIONS AND MATERIAL STRENGTH REQUIREMENTS, CHAPTER METROLOGY AND OCEANOGRAPHY Chapter Meteorology and Oceanography 1 Meteorology and Oceanography Items to be Considered for Performance Verification

### Wind shear and its effect on wind turbine noise assessment Report by David McLaughlin MIOA, of SgurrEnergy

Wind shear and its effect on wind turbine noise assessment Report by David McLaughlin MIOA, of SgurrEnergy Motivation Wind shear is widely misunderstood in the context of noise assessments. Bowdler et

### Argon Injection Optimization in Continuous Slab Casting

Argon Injection Optimization in Continuous Slab Casting Tiebiao Shi and Brian G. Thomas Department of Mechanical Engineering University of Illinois at Urbana-Champaign March 25, 2001 University of Illinois

### Homework of chapter (3)

The Islamic University of Gaza, Civil Engineering Department, Fluid mechanics-discussion, Instructor: Dr. Khalil M. Al Astal T.A: Eng. Hasan Almassri T.A: Eng. Mahmoud AlQazzaz First semester, 2013. Homework

### Techniques to achieve wind comfort & wind loads on buildings and appurtenances

Vipac Engineers & Scientists Techniques to achieve wind comfort & wind loads on buildings and appurtenances including shades, verandahs, hoardings and walls. Mr Ian Jones, Managing Director Dr Seifu Bekele,