MODELLING ANCILLARIES: WEIR COEFFICIENTS
|
|
- Suzan Cobb
- 5 years ago
- Views:
Transcription
1 WaPUG USER NOTE No 27 MODELLING ANCILLARIES: WEIR COEFFICIENTS David Balmforth, MWH 1. SCOPE This user note gives advice on the choice of coefficient for overflo eirs and orifices hen modelling storm seage overflos and bifurcations. 2. BACKGROUND Before modelling any ancillary the user must understand: the hydraulic performance of the prototype; the orkings of the algorithm in the computer model. A combined seer overflo is typically represented as a small on-line tank ith a horizontal base, horizontal eir, and horizontal ater surface. Some softare can also accommodate an overflo as a hole in the all of a manhole chamber. In each case the flo in the chamber is assumed to be subcritical and the ater level regulated by a throttle on the continuation pipe (WaPUG User Note No 2). The discharge over the eir (Q ) is determined by the head above the crest (H ) using the equation: Q = C L gh (1) n here L length of eir (or eirs if more than one) (m) g gravitational acceleration (9.81 m/s 2 ) n index, normally 1.5 C eir coefficient Alternatively the user can specify an orifice overflo, such that the discharge through the orifice overflo (Q,) is determined by the equation: Q = (2) n 0 C 0A 0 gh 0 here A 0 area of orifice (m 2 ) H 0 head across the orifice (m) n index, normally 0.5 C 0 orifice coefficient The user also has the option to specify hether the overspill goes to aste, or to the head of a specified branch. Note 27 WaPUG Page 1 of 11 Version 2 March 2009
2 A bifurcation may be modelled as a special case of an overflo orifice, but ith the crest level of the overflo placed a small vertical distance above the chamber floor (e.g. 100 mm). 3. TRANSVERSE WEIRS 3.1 Introduction Five different flo cases can occur and it is important to establish hich case is appropriate in each ancillary. Sometimes the flo case ill change during the operation of an overflo and the flo case that occurs during a verification event may be different from that hich occurs in a more extreme event (e.g. a design storm). 3.2 Case 1: Free discharge over a eir Figure 1a Free discharge over a eir The discharge is solely dependent upon the head above the crest, and is calculated by Equation 1. The eir control should be selected and the eir coefficient C, depends on the geometry of the eir crest, and Table 1 gives suitable values. Table 1 Values of C for Case 1 flo Weir crest Sharp edged 0.60 Square crest 0.70 Round crest 0.80 C Note 27 WaPUG Page 2 of 11 Version 2 March 2009
3 3.3 Case 2: Freely discharging orifice Figure 1b Freely discharging orifice The discharge is unaffected by ater levels in the overflo pipe. The upper surface of the jet springs free from the upper edge of the pipe entry, and is vented to the atmosphere. H 0 is defined as the head above the vertex of the overflo orifice, and Q 0 is calculated from Equation 2. The orifice control should be selected and C 0 given a value of Case 3: Droned Overflo overflo pipe not specified in the data file Figure 1c Droned overflo ith overflo pipe not included in model In this case H 0 is taken as the head above the vertex of the overflo pipe, but energy losses in the overflo pipe (bends, flap valves etc.) can only be accounted for in the value C 0. In this case the orifice control should be selected and C 0 calculated from: 2 C 0 = (3) K here ΣK is the sum of the loss factors for fittings in the overflo pipe. Note 27 WaPUG Page 3 of 11 Version 2 March 2009
4 Values of appropriate loss factors may be taken from Table 2 hich is based on energy loss factors for fittings in ater mains. Note that if Equation 3 gives a value in excess of 0.85 then 0.85 should be used. Table 2 Energy loss factors for pipe fittings Fitting K Sharp entry 0.5 Sharp exit o bend 1.0 Empty silt trap 3.0 Flap valve 3.0 to Case 4: Droned orifice, overflo pipe specified in the data file Figure 1d Droned overflo ith overflo pipe included in model In recent softare the overflo pipe is normally included as a second control pipe. Where an orifice entry is assumed in place of the normal entry losses, the orifice equation 2 has to represent only the energy loss at entry, and C, should be specified as 2.0. In some early softare (e.g. WASSP) H as taken as the head above the vertex until the overflo pipe surcharged. Thereafter the difference as used. The sudden change in H, hen the pipe surcharged could lead to instabilities in computation if the vertex as lo (as in a bifurcation). To overcome such problems overflo pipes ere often oversized. 3.6 Case 5: Weir droned by flo backing up from overflo pipe This flo condition is quite common. Once the overflo operates and flo builds up in the overflo pipe the eir ceases to become the dominant control. The flo is effectively Case 3 or Case 4 and should be treated as such, but ith the invert level of the overflo pipe reset to the eir crest level to give the correct overflo setting. Note 27 WaPUG Page 4 of 11 Version 2 March 2009
5 3.7 Alloance for velocity of approach Alloance for the velocity energy in flo approaching a transverse eir may be made by multiplying the eir coefficient by a factor F, here F C r = (5) 2 C r 2 H here r = H + P P height of eir crest above the chamber floor Similarly for an orifice overflo: 1 F = (6) C 0 r 2 A 0 here r = A u A u cross sectional area of flo approaching the orifice These corrections should only be used here there is an appreciable velocity of flo directly approaching the overflo. 4. MODELLING SIDE WEIRS 4.1 Introduction With side eirs the main issue that arises is the potential variation in ater level along the length of the eir due to the reduction in flo in the channel. With lo side eirs and here the incoming flo is supercritical there can also be a hydraulic jump in the channel leading to a large and unpredictable change in ater level. Lo side eirs normally have a crest belo the centre line level of the upstream seer, and this flo type occurs hen the energy at inlet exceeds tice the eir height. 2 V1 1 2C1 d + (7) 2g here d 1 = depth at the upstream end of the eir V 1 = velocity at the upstream end of the eir C 1 = height of eir crest at the upstream end of the eir Fraser (Ref 2) identified five possible flo types of side eir flo, as illustrated in Figure 2. Note 27 WaPUG Page 5 of 11 Version 2 March 2009
6 Type I Flo: Occurs ith lo side eirs in mild sloping seers. A mild sloping seer is defined as a seer here uniform flo is subcritical. Figure 2a Lo side eir The head over the eir decreases along the length of the chamber and ater levels (and hence eir discharge) are governed by conditions at inlet to the chamber, here the depth ill be beteen 0.85 and 0.90 of the critical depth. When this flo type occurs, conditions in the donstream seer have no influence on the eir discharge nor on the level of the hydraulic gradient in the upstream seer. Flo in the chamber is supercritical. Type II Flo: Occurs ith high eirs, hich usually have their crest above the centreline level of the upstream seer. Water levels in the chamber, and the eir discharge, are determined by the throttle at entry to the donstream seer, and the discharge and level of the hydraulic gradient in that seer. In this case the head on the eir increases along the length of the chamber. Flo in the chamber is subcritical. Figure 2b High side eir ith throttle Note 27 WaPUG Page 6 of 11 Version 2 March 2009
7 Type III Flo: Occurs in mild sloping seers ith lo side eirs fitted ith a throttle at the donstream end of the chamber, or ith lo side eirs here the donstream seer is surcharged. Conditions in the donstream seer influence the eir discharge but do not determine the ater level in the upstream seer. Flo in the chamber is a combination of Type I and II ith a hydraulic jump forming. Figure 2c Lo side eir on steep slope Type IV Flo: Occurs ith lo eirs in steep seers. It is similar to Type I flo but the approaching flo is uniform and d 1 approximates to the depth of uniform flo in the upstream seer. Figure 2d Lo side eir ith throttle, on steep slope Type V Flo: Occurs ith lo side eirs in steep seers here the chamber has a throttle at outlet, or here the donstream seer is surcharged. It is a combination of Types IV and II and is similar in character to Type III. A number of alternative methods exist for analysing side eir flo and calculating eir discharges. Balmforth and Sarginson (Ref 1) have revieed the various methods and explain ho the discharge capacity of side eirs can be calculated. Note 27 WaPUG Page 7 of 11 Version 2 March 2009
8 4.2 Modelling requirements - High Side Weirs Where the user is confident that the flo in the chamber is subcritical, the folloing approach is recommended. Where there is a significant variation in the head above the crest of a eir, along its length, then an alloance for this should be made in the value of the eir coefficient C. For a particular head at the donstream end of the eir the discharge over the eir should be calculated (Ref 1) or measured in situ. Denoting this head by H, and the corresponding eir discharge Q, these values should be substituted into Equation 1 and the corresponding value of C calculated. Where the flo in the chamber can be supercritical (i.e for lo side eirs). The method belo should be used. 4.3 Modelling requirements - Lo Side Weirs In models it is assumed that the flo in the chamber is governed by the continuation throttle and conditions in the donstream seer. Hoever, ith lo side eirs, ater levels and eir discharges, are governed by conditions in the upstream seer at entry to the chamber. If the actual chamber dimensions and eir coefficients are used directly in the model then the model ill over-predict the eir discharge and the ater levels in the upstream seer, as Figure 3 demonstrates. Figure 3 Model For a particular inflo, the correct eir discharge can be simulated simply by reducing the eir coefficient to give the desired result. Hoever, the ater level in the upstream seer ill be over-predicted and this can affect the discharge capability of the upstream system and flooding may be predicted here it does not occur in practice. Over-prediction of upstream ater levels can be avoided by artificially over-sizing the first seer length immediately donstream of the chamber, and if necessary reducing its gradient to maintain the correct first spill value. For Type I and IV flos the procedure is best summarised as follos: Note 27 WaPUG Page 8 of 11 Version 2 March 2009
9 (i) using proportional depth-discharge calculations for the upstream and donstream seers, determine the setting of the overflo; (ii) (iii) (iv) (v) (vi) (vii) upsize the donstream seer. An increase to tice the actual diameter is normally sufficient, though both higher and loer multiples have proved necessary at times. adjust the gradient of the oversize pipe to give the correct overflo setting by raising the donstream invert level (the ground level at this point may also have to be raised); for the upstream seer running approximately three-quarters full, calculate the eir discharge and continuation discharge using an established method of calculating side eir flo (Ref 1). Scumboards fitted to the eir reduce the discharge by 10-20%, and this should be alloed for in estimating the eir flo; using proportional depth discharge calculations, determine the depth of flo in the oversize donstream seer at the calculated continuation discharge. Calculate the drop in the level of the hydraulic gradient at the throttle using the softare's orifice equation. Add this drop to the depth in the oversize seer to give the depth at the donstream end of the chamber; the softare typically assumes a horizontal ater level and eir crest in the chamber, so that the donstream depth may no be used to determine the head on the eir and the ater level in the upstream seer. Use the former, together ith the actual eir length and the calculated eir discharge, in the softare's eir equation to obtain an equivalent eir coefficient for use in the model. This may be much smaller than traditional values; revie the calculated ater level in the upstream seer and if it is significantly higher or loer than that hich actually occurs, after the diameter of the oversize donstream seer and adjust the other parameters accordingly. When test running the model, particular attention should be paid to the conditions adjacent to the lo side eir overflo. In particular, the seer immediately donstream of the oversize pipe surcharges to any extent then Type III or V flo conditions ill probably occur in practice. In this case the donstream seer should not be oversized. For Type III and V flo the folloing procedure should be adopted: (i) (ii) (iii) model the donstream seer as built; assume the hydraulic jump forms half ay along the eir that the head along the donstream half of the eir is constant, and that the discharge over the upstream half of the eir is negligible; model the eir as a transverse eir. Use the actual eir length. If there is only one side eir, take the transverse eir coefficient (reduced by 10-20% if a scumboard is fitted), and halve it. If there are to eirs, do not halve the coefficient. With smaller side eir chambers in particular it is possible that the hole chamber becomes droned so that the eir has little effect, and the eir discharge and Note 27 WaPUG Page 9 of 11 Version 2 March 2009
10 continuation flo are determined by the size of their respective outlets. In this case it is better to model the chamber as a hole-in-manhole overflo, but ith the invert of the overflo orifice set level ith the crest of the actual eir. Note: Adoption of the above procedures ill greatly improve the simulation of the seer system containing a number of lo side eir overflos. During verification, it is permissible to make minor changes to the ancillary data provided they can be justified in the ay the ancillary has been modelled, and not purely as a means of force fitting the data. Care should be taken to identify possible Type III and V flo conditions. This is particularly true hen running a verified model ith design storms here greater surcharging may cause the flo case to change from I to II or IV to V in practice. It may be necessary therefore to amend ancillary data beteen verification and running ith design storms. Time-series rainfall should be in ith the verification data hoever. Often the data used to model lo side eirs appears strange, bearing little resemblance to actual values. This is because the on-line tank model in the softare behaves differently from the physical performance of lo side eirs, and this has to be compensated for hen specifying the ancillary data. 5. OTHER ALLOWANCES 5.1 Alloance for scumboards Where fitted, scumboards tend to reduce the discharge capacity of eirs. They can have little or no effect, or here their supports are eak they can distort and press against the eir shutting off the flo almost completely. In most cases the vertical distance beteen the underside of the scumboard and the floor of the chamber ill be much greater than the horizontal opening beteen the scumboard and the face of the eir. It is therefore the latter that usually determines ho much the flo is restricted. If the horizontal opening is greater than the maximum head on the eir then no alloance for the scumboard is needed. At other times a reduction in C, of 10% to 20% is recommended. Where ragging around scumboard supports is excessive a greater reduction should be made. 5.2 Alloance for screens Screens fitted to the crest of the eirs also tend to reduce the discharge capacity. In this situation it is better to use an equivalent eir length, shorter than the actual eir length rather than adjusting the eir coefficient. L = Actual eir length h b h b + t b here h b is the clear spacing beteen the bars (mm) t b the bar thickness (mm) If the screens are not mechanically raked, a further alloance may be necessary for ragging. For idely spaced bars rags tend to accumulate around the bars, reducing the effective dimension h b. For finer screens, rags ill completely obstruct the openings Note 27 WaPUG Page 10 of 11 Version 2 March 2009
11 beteen the bars immediately above the eir crest. The eir crest height should therefore be increased to allo for this. 6. REFERENCES 1. Balmforth D J and Sarginson E J; A comparison of methods of analysis of side eir flo, Chartered Municipal Engineer, Vol 105, No 10 pp , October Fraser W, The Behaviour of Side Weirs in Prismatic Rectangular Channels, proceedings of the Institution of Civil Engineers, Vol 6, February AMENDMENTS Ver Description Date 1. First Published August Revision incorporating material from user note 14 March 2009 Note 27 WaPUG Page 11 of 11 Version 2 March 2009
Modelling of Pressurised Pipes within InfoWorks ICM and CS
Modelling of Pressurised Pipes within InfoWorks ICM and CS 1. Introduction Correctly modelling pressurised pipes, variously described as forcemains or rising mains, can be one of the more difficult aspects
More informationI.CHEM.E. SYMPOSIUM SERIES NO. 97 BUOYANCY-DRIVEN NATURAL VENTILATION OP ENCLOSED SPACES
BUOYANCY-DRIVEN NATURAL VENTILATION OP ENCLOSED SPACES M. R. Marshall* and P. L. Stewart-Darling* A simple mathematical model for the buoyancy driven ventilation of an enclosed space, using a two-pipe
More informationANSWERS TO QUESTIONS IN THE NOTES AUTUMN 2018
ANSWERS TO QUESTIONS IN THE NOTES AUTUMN 2018 Section 1.2 Example. The discharge in a channel with bottom width 3 m is 12 m 3 s 1. If Manning s n is 0.013 m -1/3 s and the streamwise slope is 1 in 200,
More informationResearch on ESC Hydraulic Control Unit Property and Pressure Estimation
Research on ESC Hydraulic Control Unit Property and Pressure Estimation Liu Wei, Ding Haitao *, and Guo Konghui State Key Libratory of Automobile Dynamic Simulation, Jilin University, Changchun 30025,
More informationLecture 10 : Sewer Appurtenances
1 P age Module 8 : Sewer Appurtenances Lecture 10 : Sewer Appurtenances 2 P age The structures, which are constructed at suitable intervals along the sewerage system to help its efficient operation and
More information3. GRADUALLY-VARIED FLOW (GVF) AUTUMN 2018
3. GRADUALLY-VARIED FLOW (GVF) AUTUMN 2018 3.1 Normal Flow vs Gradually-Varied Flow V 2 /2g EGL (energy grade line) Friction slope S f h Geometric slope S 0 In flow the downslope component of weight balances
More information2 1 Minor clarification to text and figures.
WaPUG Guide The Design of CSO Chambers to Incorporate Screens Copyright 2006 WaPUG This entire document may be freely copied provided that the text is reproduced in full, the source acknowledged, and provided
More informationAir Cylinders Drive System Full Stroke Time & Stroke End Velocity
Full Time & End Velocity Ho to Read the Graph This graph shos the full stroke time and stroke hen a cylinder drive system is composed of the As the graph shon belo, various load ratio and full stroke time
More informationEXPERIMENTAL STUDY ON THE DISCHARGE CHARACTERISTICS OF SLUICE FOR TIDAL POWER PLANT
EXPERIMENTAL STUDY ON THE DISCHARGE CHARACTERISTICS OF SLUICE FOR TIDAL POWER PLANT Sang-Ho Oh 1, Kwang Soo Lee 1 and Dal Soo Lee 1 The discharge characteristics of sluice caisson for tidal power plant
More informationExperiment 8: Minor Losses
Experiment 8: Minor Losses Purpose: To determine the loss factors for flow through a range of pipe fittings including bends, a contraction, an enlargement and a gate-valve. Introduction: Energy losses
More informationAdvanced Hydraulics Prof. Dr. Suresh A. Kartha Department of Civil Engineering Indian Institute of Technology, Guwahati
Advanced Hydraulics Prof. Dr. Suresh A. Kartha Department of Civil Engineering Indian Institute of Technology, Guwahati Module - 4 Hydraulics Jumps Lecture - 4 Features of Hydraulic Jumps (Refer Slide
More informationExperiment (13): Flow channel
Experiment (13): Flow channel Introduction: An open channel is a duct in which the liquid flows with a free surface exposed to atmospheric pressure. Along the length of the duct, the pressure at the surface
More informationEffect of channel slope on flow characteristics of undular hydraulic jumps
River Basin Management III 33 Effect of channel slope on flow characteristics of undular hydraulic jumps H. Gotoh, Y. Yasuda & I. Ohtsu Department of Civil Engineering, College of Science and Technology,
More informationExercise (4): Open Channel Flow - Gradually Varied Flow
Exercise (4): Open Channel Flow - Gradually Varied Flow 1) A wide channel consists of three long reaches and has two gates located midway of the first and last reaches. The bed slopes for the three reaches
More informationGerald D. Anderson. Education Technical Specialist
Gerald D. Anderson Education Technical Specialist The factors which influence selection of equipment for a liquid level control loop interact significantly. Analyses of these factors and their interactions
More informationOPEN CHANNEL FLOW WORKSHEET 3 WATER SURFACE PROFILES
Learning Objectives OPEN CHANNEL FLOW WORKSHEET 3 WATER SURFACE PROFILES 1. Learn about gradually varied flow and rapidly varying flow 2. Discuss different types of water surface profiles 3. Discuss the
More informationCONTROL VALVE WHAT YOU NEED TO LEARN?
CONTROL VALVE WHAT YOU NEED TO LEARN? i) The control valve characteristics refers to the relationship between the volumetric flowrate F (Y-axis) through the valve AND the valve travel or opening position
More informationHY-8 Version 7.2 Build Date January 17, Federal Highway Administration.
HY-8 Version 7.2 Build Date January 17, 2012 Federal Highway Administration http://www.fhwa.dot.gov/engineering/hydraulics/software/hy8/index.cfm SIMPLE Simple to use Use for simple culverts and bridges
More informationInternational Journal of Technical Research and Applications e-issn: , Volume 4, Issue 3 (May-June, 2016), PP.
DESIGN AND ANALYSIS OF FEED CHECK VALVE AS CONTROL VALVE USING CFD SOFTWARE R.Nikhil M.Tech Student Industrial & Production Engineering National Institute of Engineering Mysuru, Karnataka, India -570008
More informationAPPENDIX B HYDRAULIC DESIGN DATA FOR CULVERTS
TM 5-820-4/AFM 88-5, Chap 4 APPENDIX B HYDRAULIC DESIGN DATA FOR CULVERTS B-1. General. a. This appendix presents diagrams, charts, coefficients and related information useful in design of culverts. The
More informationFree Surface Flow Simulation with ACUSIM in the Water Industry
Free Surface Flow Simulation with ACUSIM in the Water Industry Tuan Ta Research Scientist, Innovation, Thames Water Kempton Water Treatment Works, Innovation, Feltham Hill Road, Hanworth, TW13 6XH, UK.
More information2. RAPIDLY-VARIED FLOW (RVF) AUTUMN 2018
2. RAPIDLY-VARIED FLOW (RVF) AUTUMN 2018 Rapidly-varied flow is a significant change in water depth over a short distance (a few times water depth). It occurs where there is a local disturbance to the
More informationAdvanced Hydraulics Prof. Dr. Suresh A. Kartha Department of Civil Engineering Indian Institute of Technology, Guwahati
Advanced Hydraulics Prof. Dr. Suresh A. Kartha Department of Civil Engineering Indian Institute of Technology, Guwahati Module - 4 Hydraulic Jumps Lecture - 1 Rapidly Varied Flow- Introduction Welcome
More informationHours / 100 Marks Seat No.
17421 15116 3 Hours / 100 Seat No. Instructions (1) All Questions are Compulsory. (2) Answer each next main Question on a new page. (3) Illustrate your answers with neat sketches wherever necessary. (4)
More informationHours / 100 Marks Seat No.
17421 21415 3 Hours / 100 Marks Seat No. Instructions : (1) All Questions are compulsory. (2) Answer each next main Question on a new page. (3) Illustrate your answers with neat sketches wherever necessary.
More informationEXAMPLES (OPEN-CHANNEL FLOW) AUTUMN 2018
EXAMPLES (OPEN-CHANNEL FLOW) AUTUMN 2018 Normal and Critical Depths Q1. If the discharge in a channel of width 5 m is 20 m 3 s 1 and Manning s n is 0.02 m 1/3 s, find: (a) the normal depth and Froude number
More informationEvaluating Surge Potential in CSO Tunnels
14 Evaluating Surge Potential in CSO Tunnels Karen E. Ridgway Tunnels are being proposed to control combined sewer overflow (CSO) in numerous cities in the United States and Canada. The tunnels are intended
More information19.1 Problem: Maximum Discharge
19.1 Problem: Maximum Discharge In partially full channel having an equilateral triangular cross section, the rate of discharge is Q = KAR/3 in which K is a constant, A flow area, R is the hydraulic mean
More informationEffect of Fluid Density and Temperature on Discharge Coefficient of Ogee Spillways Using Physical Models
RESEARCH ARTICLE Effect of Fluid Density and Temperature on Discharge Coefficient of Ogee Spillways Using Physical Models M. SREENIVASULU REDDY 1 DR Y. RAMALINGA REDDY 2 Assistant Professor, School of
More informationANNEX 18. RESOLUTION MSC.362(92) (Adopted on 14 June 2013) REVISED RECOMMENDATION ON A STANDARD METHOD FOR EVALUATING CROSS-FLOODING ARRANGEMENTS
MSC 92/26/Add. Annex 8, page ANNEX 8 RESOLUTION MSC.362(92) (Adopted on 4 June 203) REVISED RECOMMENDATION ON A STANDARD METHOD FOR EVALUATING CROSS-FLOODING ARRANGEMENTS THE MARITIME SAFETY COMMITTEE,
More informationSediment Basin 7E-12. Design Manual Chapter 7 - Erosion and Sediment Control 7E - Design Information for ESC Measures BENEFITS.
7E-12 Design Manual Chapter 7 - Erosion and Sediment Control 7E - Design Information for ESC Measures Sediment Basin BENEFITS Flow Control Erosion Control Sediment Control Runoff Reduction Flow Diversion
More informationROSE-HULMAN INSTITUTE OF TECHNOLOGY Department of Mechanical Engineering. Mini-project 3 Tennis ball launcher
Mini-project 3 Tennis ball launcher Mini-Project 3 requires you to use MATLAB to model the trajectory of a tennis ball being shot from a tennis ball launcher to a player. The tennis ball trajectory model
More informationDAIVÕES DAM SPILLWAY: A NOVEL SOLUTION FOR THE STILLING BASIN
DAIVÕES DAM SPILLWAY: A NOVEL SOLUTION FOR THE STILLING BASIN Elsa Alves *, Felix Hernando and Rafael Chacón * Laboratório Nacional de Engenharia Civil (LNEC) Av. do Brasil, 101, 1700-066 Lisboa, Portugal
More informationBY THOMAS M. WALSKI, BRIAN LUBENOW, AND JEFFREY SPAIDE. When they install a branch from a water distribution main,
BY THOMAS M. WALSKI, BRIAN LUBENOW, AND JEFFREY SPAIDE When they install a branch from a water distribution main, water utility managers often debate the benefits of using a tap as opposed to shutting
More informationPlan B Dam Breach Assessment
Plan B Dam Breach Assessment Introduction In support of the Local Sponsor permit applications to the states of Minnesota and North Dakota, a dam breach analysis for the Plan B alignment of the Fargo-Moorhead
More informationAIRFLOW 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 informationThe tensile capacity of suction caissons in sand under rapid loading
Frontiers in Offshore Geotechnics: ISFOG 25 Gourvenec & Cassidy (eds) 25 Taylor & Francis Group, London, ISBN 415 3963 X The tensile capacity of suction caissons in sand under rapid loading Guy T. Houlsby,
More informationOIL SUPPLY SYSTEMS ABOVE 45kW OUTPUT 4.1 Oil Supply
OIL SUPPLY SYSTEMS ABOVE 45kW OUTPUT 4.1 Oil Supply 4.1.1 General The primary function of a system for handling fuel oil is to transfer oil from the storage tank to the oil burner at specified conditions
More information2O-2 Open Channel Flow
Iowa Stormwater Management Manual O- O- Open Channel Flow A. Introduction The beginning of any channel design or modification is to understand the hydraulics of the stream. The procedures for performing
More informationUNIT 15 WATER HAMMER AND SURGE TANKS
UNT 15 WATER HAMMER AND SURGE TANKS Structure 15.1 ntroduction Objectives 15.2 Water Hammer 15.2.1 Expression for Rise in Pressure 15.3 Rapid Acceleration of Flow 15.4 Surge Tanks 15.5 Summary 15.6 Keywords
More informationOIL AND GAS INDUSTRY
This case study discusses the sizing of a coalescer filter and demonstrates its fouling life cycle analysis using a Flownex model which implements two new pressure loss components: - A rated pressure loss
More informationDigital Computer Simulation of a Reciprocating Compressor-A Simplified Analysis
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 1972 Digital Computer Simulation of a Reciprocating Compressor-A Simplified Analysis D.
More informationCONSIDERATION OF DENSITY VARIATIONS IN THE DESIGN OF A VENTILATION SYSTEM FOR ROAD TUNNELS
- 56 - CONSIDERATION OF DENSITY VARIATIONS IN THE DESIGN OF A VENTILATION SYSTEM FOR ROAD TUNNELS Gloth O., Rudolf A. ILF Consulting Engineers Zürich, Switzerland ABSTRACT This article investigates the
More informationBC Ministry of Forests. March Fish Stream Crossing Guidebook. Forest Practices Code of British Columbia.
FRST 557 Lecture 7c Bridges and Culverts: Water Velocity and Discharge Lesson Background and Overview: The previous two lessons presented methods for estimating water volume flow at a particular site and
More informationGeneral Information for Culvert Design
Design Manual Chapter 2 - Stormwater 2E - Culvert Design 2E-1 General Information for Culvert Design A. Introduction A culvert is a conduit under an embankment that transports stormwater from one side
More informationAPPLYING VARIABLE SPEED PRESSURE LIMITING CONTROL DRIVER FIRE PUMPS. SEC Project No
APPLYING VARIABLE SPEED PRESSURE LIMITING CONTROL DRIVER FIRE PUMPS SEC Project No. 1803007-000 November 20, 2006 TABLE OF CONTENTS I. ABSTRACT...1 II. INTRODUCTION...1 III. HISTORY...2 IV. VARIABLE SPEED
More informationON-BOTTOM STABILITY CALCULATIONS FOR FIBRE OPTIC SUBMARINE CABLES
ON-BOTTOM STABILITY CALCULATIONS FOR FIBRE OPTIC SUBMARINE CABLES Inge Vintermyr (Nexans ray AS) Email: Nexans ray AS, PO.Box 6450 Etterstad, N-0605 Oslo, ray. Abstract: This
More informationAalborg Universitet. Published in: Proceedings of Offshore Wind 2007 Conference & Exhibition. Publication date: 2007
Aalborg Universitet Design Loads on Platforms on Offshore wind Turbine Foundations with Respect to Vertical Wave Run-up Damsgaard, Mathilde L.; Gravesen, Helge; Andersen, Thomas Lykke Published in: Proceedings
More informationSection 5: Pond Outlets
Section : Pond Outlets Defining and calculating pond outlet devices 8 Minutes Press Space, PageDown, or Click to advance. Press PageUp to reverse. Esc to exit. Right-Click for other options. Outlets Introduction
More information2.2.2 The righting lever GZ shall be at least 0.2 m at an angle of heel equal to or greater than 30.
Page 13 2.2.2 The righting lever GZ shall be at least 0.2 m at an angle of heel equal to or greater than 30. 2.2.3 The maximum righting lever shall occur at an angle of heel not less than 25. If this is
More information09 - Choosing /sizing a cylinder and valve
- Choosing /sizing a cylinder and valve - Pipe flow resistence - Valve sizing - Cylinder sizing LII PIPE FLOW RESISTENCE Flow rate Qn Flow rate is calculated as the volume at normal conditions ( atmospheric
More information6.6 Gradually Varied Flow
6.6 Gradually Varied Flow Non-uniform flow is a flow for which the depth of flow is varied. This varied flow can be either Gradually varied flow (GVF) or Rapidly varied flow (RVF). uch situations occur
More informationHYDRAULIC JUMP AND WEIR FLOW
HYDRAULIC JUMP AND WEIR FLOW 1 Condition for formation of hydraulic jump When depth of flow is forced to change from a supercritical depth to a subcritical depth Or Froude number decreases from greater
More informationHydraulic Engineering
PDHonline Course H146 (4 PDH) Hydraulic Engineering Instructor: Mohamed Elsanabary, Ph.D., Prov. Lic. Engineering. 2013 PDH Online PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030-6658 Phone & Fax:
More informationCSO/STORMWATER MANAGEMENT. HYDROVEX VHV / SVHV Vertical Vortex Flow Regulator
CSO/STORMWATER MANAGEMENT HYDROVEX VHV / SVHV Vertical Vortex Flow Regulator HYDROVEX VHV / SVHV VERTICAL VORTEX FLOW REGULATOR APPLICATIONS One of the major problems of urban wet weather flow management
More informationTransition Submergence and Hysteresis Effects in Three-Foot Cutthroat Flumes
Transition Submergence and Hysteresis Effects in Three-Foot Cutthroat Flumes Why Measure Water for Irrigation? (You had to ask.) Improve: Accuracy Convenience Economics Water Measurement Manual (Door Prize)
More informationLow Gradient Velocity Control Short Term Steep Gradient Channel Lining Medium-Long Term Outlet Control Soil Treatment Permanent [1]
Check Dams DRAINAGE CONTROL TECHNIQUE Low Gradient Velocity Control Short Term Steep Gradient Channel Lining Medium-Long Term Outlet Control Soil Treatment Permanent [1] [1] Though not generally considered
More informationComponents of a Barrage
Components of a Barrage Definition The only difference between a weir and a barrage is of gates, that is the flow in barrage is regulated by gates and that in weirs, by its crest height. Barrages are costlier
More informationBACK PRESSURE / SUSTAINING
In many liquid piping systems, it is vital that line pressure is maintained within relatively narrow limits. This is the function of the 108 Pressure Relief / Back Pressure Series of the OCV control valves.
More informationInfluence 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 informationSelecting Flow Metering Sites And Evaluating Data
Insert Slide Title Here Selecting Flow Metering Sites And Evaluating Data Patrick L. Stevens, PE Luis Mijares PStevens2@Idexcorp.com LMijares@Idexcorp.com ADS Environmental Services Strategy for Selecting
More informationFLOW 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 informationBroadly speaking, there are four different types of structures, each with its own particular function:
3 The selection of structures 3.1 Introduction In selecting a suitable structure to measure or regulate the flow rate in open channels, all demands that will be made upon the structure should be listed.
More informationOperational Behaviour of Safety Valves with Constant Superimposed Backpressure
Operational Behaviour of Safety Valves with Constant Superimposed Backpressure Arne Gastberg Albert Richter ARI-Armaturen GmbH & Co. KG When selecting spring loaded safety valves, an accurate knowledge
More informationCORESTA RECOMMENDED METHOD N 6
CORESTA RECOMMENDED METHOD N 6 DETERMINATION OF VENTILATION DEFINITIONS AND MEASUREMENT PRINCIPLES (2015 Revision September 2016) 1. SCOPE This CORESTA Recommended Method specifies a method for the determination
More information(Refer Slide Time: 2:16)
Fluid Machines. Professor Sankar Kumar Som. Department Of Mechanical Engineering. Indian Institute Of Technology Kharagpur. Lecture-23. Diffuser and Cavitation. Good morning and welcome you all to this
More informationAnalysis of pressure losses in the diffuser of a control valve
Analysis of pressure losses in the diffuser of a control valve Petr Turecký 1, Lukáš Mrózek 2*, Ladislav Taj 2, and Michal Kolovratník 3 1 ENVIROS, s.r.o., Dykova 53/10, 101 00 Praha 10-Vinohrady, Czech
More informationExercise (3): Open Channel Flow Rapidly Varied Flow
Exercise (3): Open Channel Flow Rapidly Varied Flow 1) A hydraulic jump exists in a trapezoidal channel having a bed width of 7 m and side slope of 1:1. The flowing discharge is 25 m 3 /sec. Construct
More informationBACK PRESSURE / SUSTAINING
SPECIFICATIONS DIMENSIONS In many liquid piping systems, it is vital that line pressure is maintained within relatively narrow limits. This is the function of the 108 Pressure Relief / Back Pressure Series
More informationCHAPTER 7 : SMOKE METERS AND THEIR INSTALLATIONS
CHAPTER 7 : SMOKE METERS AND THEIR INSTALLATIONS 1 Scope : This Chapter covers the requirements of smoke meters and their installation on engines for full load and free acceleration tests, mentioned in
More informationTHE EFFECTS OF RAINFALL INTENSITY, PAVEMENT CROSS SLOPE, SURFACE TEXTURE, AND DRAINAGE LENGTH ON PAVEMENT WATER DEPTHS
THE EFFECTS OF RANFALL NTENSTY, PAVEMENT CROSS SLOPE, SURFACE TEXTURE, AND DRANAGE LENGTH ON PAVEMENT WATER DEPTHS " :".., r.. r '('.,.. -.-. - SUMMARY REPORT.... of Research Report Number 138-5 Study
More informationSUMMARY PROBLEMS CAUSED BY BACKFLOW IN PIPE SYSTEMS.
Page 1 of 11 SUMMARY There are many problems derived from a reverse flow in a piping system. A solution presented in this paper is the WaStop inline check valve. The paper aims to explain some of the important
More informationAkasison 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
More informationINTERNATIONAL JOURNAL OF CIVIL AND STRUCTURAL ENGINEERING Volume 3, No 1, 2012
INTERNATIONAL JOURNAL OF CIVIL AND STRUCTURAL ENGINEERING Volume 3, No 1, 2012 Copyright by the authors - Licensee IPA- Under Creative Commons license 3.0 Research article ISSN 0976 4399 ABSTRACT Scour
More informationCritical 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 informationSSO 700 Integrated Watershed Action Plan: Continuous Calibration of a Model
SSO 700 Integrated Watershed Action Plan: Continuous Calibration of a Model 5 Cities Plus August 16, 2017 Presented by Matt Spidare, P.E MSDGC Victoria Berry, P.E. CH2M Overview of Presentation Project
More informationAutodesk Moldflow Communicator Process settings
Autodesk Moldflow Communicator 212 Process settings Revision 1, 3 March 211. Contents Chapter 1 Process settings....................................... 1 Profiles.................................................
More informationCrispin Valves Technical Reference Manual. Crispin
Crispin Valves Technical Reference Manual Crispin Since 1905 Crispin Multiplex Manufacturing Co. 600 Fowler Avenue Berwick, PA 18603 1-800-AIR-VALV T: (570) 752-4524 F: (570) 752-4962 www.crispinvalve.com
More informationThis portion of the piping tutorial covers control valve sizing, control valves, and the use of nodes.
Piping Tutorial A piping network represents the flow of fluids through several pieces of equipment. If sufficient variables (flow rate and pressure) are specified on the piping network, CHEMCAD calculates
More informationDESIGN OF BELL-MOUTH SPILLWAY AT BARVI DAM
DESIGN OF BELL-MOUTH SPILLWAY AT BARVI DAM Akshay Haldankar 1, Mahesh Bhadra 2, Rahul Harad 3, Darpan Kapre 4, Dipali Patil 5 1,2,3,4 Under graduate,dept. of Civil Engineering, DRIEMS Neral. 5Assistant
More informationEffects 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 informationRate of Flow Valve Series 120
SPECIFICATIONS Rate of Flow Valve Series DIMENSIONS The OCV Series 120 Rate of Flow control valve is designed to control or limit flow to a predetermined rate, regardless offl uctuations in downstream
More informationDesign of a High Efficiency Scroll Wrap Profile for Alternative Refrigerant R410A
Purdue University Purdue e-pubs International Compressor Engineering Conference School of Mechanical Engineering 1998 Design of a High Efficiency Scroll Wrap Profile for Alternative Refrigerant R410A J.
More informationYasuyuki Hirose 1. Abstract
Study on Tsunami force for PC box girder Yasuyuki Hirose 1 Abstract In this study, a waterway experiment was performed in order to understand the influence of tsunami forms on tsunami forces acting on
More informationA centrifugal pump consists of an impeller attached to and rotating with the shaft and a casing that encloses the impeller.
Centrifugal pump How centrifugal pumps work A centrifugal pump consists of an impeller attached to and rotating with the shaft and a casing that encloses the impeller. In centrifugal pump, liquid is forced
More information3 1 PRESSURE. This is illustrated in Fig. 3 3.
P = 3 psi 66 FLUID MECHANICS 150 pounds A feet = 50 in P = 6 psi P = s W 150 lbf n = = 50 in = 3 psi A feet FIGURE 3 1 The normal stress (or pressure ) on the feet of a chubby person is much greater than
More informationOPTIMIZATION OF SINGLE STAGE AXIAL FLOW COMPRESSOR FOR DIFFERENT ROTATIONAL SPEED USING CFD
http:// OPTIMIZATION OF SINGLE STAGE AXIAL FLOW COMPRESSOR FOR DIFFERENT ROTATIONAL SPEED USING CFD Anand Kumar S malipatil 1, Anantharaja M.H 2 1,2 Department of Thermal Power Engineering, VTU-RO Gulbarga,
More informationNUMERICAL INVESTIGATION ON WATER DISCHARGE CAPABILITY OF SLUICE CAISSON OF TIDAL POWER PLANT
Proceedings of the Sixth International Conference on Asian and Pacific Coasts (APAC ) December 4 6,, Hong Kong, China NUMERICAL INVESTIGATION ON WATER DISCHARGE CAPABILITY OF SLUICE CAISSON OF TIDAL POWER
More informationGrit chambers are basin to remove the inorganic particles to prevent damage to the pumps, and to prevent their accumulation in sludge digestors.
Home Lecture Quiz Design Example Grit Chambers Types of Grit Chambers Aerated Grit Chamber Principle of Working of Grit Chamber Design of Grit Chambers Primary Sedimentation Grit Chambers Grit chambers
More informationConstruction, Fitting and Testing of Closed Fuel Overflow Systems
Construction, Fitting and Testing of Closed Fuel Overflow Systems 2014 This latest edition incorporates all rule changes. The latest revisions are shown with a vertical line. The section title is framed
More informationPractical Guide. By Steven T. Taylor, P.E., Member ASHRAE
ractical Guide The following article was published in ASHRAE Journal, March 2003. Copyright 2003 American Society of Heating, Refrigerating and Air- Conditioning Engineers, Inc. It is presented for educational
More informationNumerical modeling of refraction and diffraction
Numerical modeling of refraction and diffraction L. Balas, A. inan Civil Engineering Department, Gazi University, Turkey Abstract A numerical model which simulates the propagation of waves over a complex
More informationCHAPTER 4 SPALDING COUNTY, GEORGIA 4.0 CULVERT DESIGN
SPALDING COUNTY, GEORGIA CHAPTER 4 4.0 CULVERT DESIGN... 4-1 4.1 INTRODUCTION... 4-1 4.2 SYMBOLS AND DEFINITIONS... 4-1 4.3 ENGINEERING DESIGN CRITERIA... 4-2 4.3.1 FREQUENCY FLOOD... 4-2 4.3.2 VELOCITY
More informationINTERACTION BETWEEN WIND-DRIVEN AND BUOYANCY-DRIVEN NATURAL VENTILATION Bo Wang, Foster and Partners, London, UK
INTERACTION BETWEEN WIND-DRIVEN AND BUOYANCY-DRIVEN NATURAL VENTILATION Bo Wang, Foster and Partners, London, UK ABSTRACT Ventilation stacks are becoming increasingly common in the design of naturally
More informationWater Weir Flow Controller. Introduction. Safety Precautions. Mounting the Hardware
57007-88 Introduction Safety Precautions This instruction sheet describes how to set up and use the Hach (Figure 1). A water weir is a device that raises or diverts water to regulate the flow. Hach s water
More informationExperimental Investigation on Changes of Water Surface Profile with Gaussian Shaped Bottom and Side Roughness
Experimental Investigation on Changes of Water Surface Profile with Gaussian Shaped Bottom and Side Md. Rafiue Islam a, Shariful Islam b*, Md. Abdul Qaiyum Talukder c, S. M. Rezwan Hossain d Abstract Bed
More informationMODELLING OF FUME EXTRACTORS C. R.
LD8 19th International Symposium of Ballistics, 7 11 May 21, Interlaken, Switzerland MODELLING OF FUME EXTRACTORS C. R. Woodley WS4 Guns and Warheads Department, Defence Evaluation and Research Agency,
More informationAIR-WATER FLOW STRUCTURES AT AN ABRUPT DROP WITH SUPERCRITICAL FLOW
AIR-WATER FLOW STRUCTURES AT AN ABRUPT DROP WITH SUPERCRITICAL FLOW H. CHANSON and L. TOOMBES Department of Civil Engineering, The University of Queensland, Brisbane QLD 4072, Australia 1. Introduction
More informationFisher DVI Desuperheater Venturi Inline
Instruction Manual DVI Desuperheater Fisher DVI Desuperheater Venturi Inline Contents Introduction... 1 Scope of Manual... 1 Description... 1 Principle of Operation... 2 Installation... 3 Operating Instructions...
More informationThe Basics of Culvert and Inlet Design
PDHonline Course C619 (8 PDH) The Basics of Culvert and Inlet Design Jerry D. Morrow, PE 2013 PDH Online PDH Center 5272 Meadow Estates Drive Fairfax, VA 22030 6658 Phone & Fax: 703 988 0088 www.pdhonline.org
More information