Venturi Definition and 113 Threads

  1. G

    Flow rate/pressure in a venturi

    Homework Statement Hi Guys, I have found that as flow rate increases the pressure difference in the sections of the venturi increases. Would someone please mind explaining in words why as I'm not sure. Homework EquationsThe Attempt at a Solution Well I know that when the fluid gets to a...
  2. M

    Venturi, how does fluid go from low P tube to high P tube

    Homework Statement How does fluid move from low pressure area in a Venturi to a high pressure area, which is downstream from the Venturi. Homework EquationsThe Attempt at a Solution Not understanding the mechanism here, as I thought fluids only go from high pressure to low presure. Since the...
  3. cellurl

    DIY Leaf-Vacuum: Using Venturi Equations for Pressure Calculation

    I want to make a leaf-vacuum using a leaf-blower. Does anyone know how I might calculate the pressures? Thanks!
  4. H

    What are the air speeds in a Venturi meter with varying tube diameters?

    Homework Statement Air is blown through a horizontal Venturi tube. The diameters of the narrow and wider sections of the tube are 1.0 cm and 3.0 cm respectively, and the height h of the mercury column is measured to be 1.00 mm. What are the air speeds in the wider and the narrower sections of...
  5. P

    Fluid Mechanics Venturi meter/manometer

    Homework Statement Question: http://i.imgur.com/aoXUDP1.png Homework Equations Q=v1A1=v2A2 Bernoullis Equation P=P0 + ρgh The Attempt at a Solution I have got an answer of 3.55*10^-3 m^3 /s. The answer i have been told is 1.29 x 10-3 m3s-1. I am not sure if i am wrong or the answer...
  6. crador

    Fluid Dynamics pipeline with a venturi injector

    Hey guys, I've been wracking my brain for a while, and thus I have landed here yet again. My problem is the following: Say you have a pipeline with a venturi injector, and intermittently a large tank of water with a portion of air on top -- I.e. a closed circuit communicating between the...
  7. N

    Thermofluids: Air Flow Measurement (Pitot & Venturi)

    Homework Statement I did an experiment to measure air flow using a pitot static tube and a venturi meter. First attempt: I connected both long and short manometers to the pitot static tube. Then I switch on the fan. The difference in manometer reading is 0.59kPa, which is the pressure. Then I...
  8. P

    Fluid Mechanics and Venturi meter

    Homework Statement A Venturi meter is constructed with an inlet diameterof 100 mm and a throat diameter of 40 mm. The meter must be calibrated prior to leaving the factory. The meter is installed in a 100 mm diameter water main with a...
  9. J

    Can a Faster Valve Improve Venturi Pump Cycling Speed?

    I am looking to cycle on/off rapidly a venturi pump. I am using a solenoid valve but is there a recommendation for a quicker valve type or regulator? Speed is my most important requirement. Thank you.
  10. T

    Venturi Tube Question: Help Solve & Find the Right Answer

    Hey guys. I can't figure out part 3bii) of this Venturi Tube Question. The answer I keep getting is 3.7907E-03 but it should be 3.95E-03. I'm definitely missing something but can't figure out what. I'm out by about 5%, could it just be down to rounding errors? Question and my working is...
  11. S

    Bernoulli principle and venturi effect.

    I have a specific problem involving two reservoirs filled with water with a height difference Y and total head H, and was wondering if a venturi like device could be used to calculate the resulting pressure head x and if it will exceed the bottom of reservoir 1. Also the drain length is d...
  12. S

    Flow through a venturi meter (TEL)

    Homework Statement I recently completed an experiment which analysed flow through a venturi meter. We were then asked to plot the total energy line, velocity head line and pressure head line across 11 piezometers connected to the pipeline. Homework Equations ## \frac{P_1}{\rho g} + z_1 +...
  13. P

    Building a Venturi to Collect Hazelnuts

    Hi all, We are trying to build a venturi and I have got a couple of questions. I am not an engineer actually, and I am working together with 2 mechanical engineers who graduated and forgot everything long time ago :) We are trying to build this venturi to collect hazelnuts from the...
  14. F

    Flow measurement in venturi meter

    First I am trying to find the theoretical flow rate but I am not able to get the answer because since diameter of the pipe is 0.03m throughout, when I sub into the formula: My A1/A2 will be 1, and 1-1 = 0. And I will get maths error whatever is divided by 0. Am I going in the wrong direction...
  15. S

    Venturi Calculation for a Carburettor

    Hi there, I am in my first year at uni studying aeronautical engineering and I am doing a group project where we have to design and build a carburettor. We have to calculate the venturi size for the narrower section The capacity of the engine is 166cc and it is 4 stroke We are going to...
  16. P

    Need a formula that combines the stack effect + venturi effect to find Q

    Hi, I'm trying to find Q for chimney/stove that looks very similar to the picture attached. I was going to use the formula below, but I realized that it does not account for the venturi effect if a chimney was conical in shape - i.e. smaller at the top vs. the base. Nor does it account for...
  17. H

    Bernoulli's Principle with a Venturi Tube, find flow rate

    So that's the question and I'm stuck on Part b. I don't even know how to approach it. I know A1= 3A2 but I don't know A1 and I need V2 and I don't know V1 or A2. I'm just confused as to how to do this. Please help!
  18. D

    Help me calculate venturi flow rate

    Hi I have a challenge (Its over 30 years since I did physics). I have the following information and I want to calculate the flow rate change . Opening diameter 2m , narrows smoothly to diameter 1m. Seawater, tidal flow of 2.5 m/s into the opening, what is the effective flow rate in the throat...
  19. E

    Pressure theory applied to a Venturi tube

    Hi, I'm a little confused about the pressure in the inlet/outlet and the throat of a Venturi tube. Why is the pressure in the inlet/outlet greater than in the throat? I thought that because air is needed to flow into a smaller space so the pressure has to be greater? Pardon me. I've...
  20. F

    Will a venturi work if the pressure behind it is

    it was pointed out to me that a venturi won't function if the pressure differential before and after the venturi is minimal. how much pressure differential is required for it to work? ty, john
  21. F

    Venturi Principle: Is p1=p3 and v1=v3?

    Just simply, from the diagram above is p1=p3 and v1=v3? Thanks Dan
  22. D

    Flow rate measurement: Venturi vs Sharp edged circular orifice. Help

    Flow rate measurement: Venturi vs Sharp edged circular orifice. Help! :) Homework Statement Hello guys, I am having trouble answering these questions. I know the the discharge coefficient for a venturi is always higher than that of the sharp edge orifice. Can you guys help me out with the...
  23. S

    Hair-brained venturi idea, will it work?

    Hi, I know a little about a little and nothing about a lot, but I've got an idea and I thought this community may be able to lend a hand. Perhaps even find it interesting, who knows. I'm working on a race car, and I need to deal with pressure that can build in the crankcase because piston...
  24. P

    Venturi tube to suck steam from hut

    Hi All, I am designing a vertical venturi tube to be inserted into a 18" piece of ductwork in order to pull steam generated in a 12'' perpendicular duct. I would like to reduce the diameter from 18'' to 6'' at which point i will tie in the 12'' perpendicular duct (nozzled down in size) in...
  25. P

    Calculating Air Pressure, Velocity at Venturi Tube Inlet/Throat/Outlet

    Im a new to this site because my have a question that i don't know how to answer and it really confusing me. If it possible, can you guys show me step by step on how to solve it. A venturi tube has an inlet diameter of 3.0 inches, a throat diameter of 1.5 inches and an outlet diameter of 3.5...
  26. A

    How does the venturi effect allow gas burners to operate without electricity?

    Hi guys I have a question regarding the working principle of gas burner. I was always have this question " How gas burner works using gas pressure lower -after been regulated- than atmospheric air ? " Won't the the atmospheric air pressure prevent the gas from flowing? Gas Burners Both...
  27. W

    What is the solution for a venturi tube with water flow and pressure changes?

    Homework Statement I have a question involving a venturi tube - Air flows through the channel of a venturi of constant width 0.06m. Compressibility and viscous effects are negligible. a) Determine the flowrate when water is drawn up 0.10m in a small tube attached to the static pressure tap...
  28. P

    Venturi tube obeys ideal gas law?

    The ideal gas law staes that pressure is inversely proportional to volume. Makes sense but I am confused by what happens in a venturi tube, where volume seems to decrease at the same time that pressure decreases also. I understand that dynamic pressure increases in the throat but what am I...
  29. T

    Venturi tube help needed in determining pressure difference

    Homework Statement Water flows through venturi tube at 0.3 litres/s. Diameter of venturi tube is 32mm to 20mm to 32mm and the water density is 1000kg/m^3. Homework Equations a) Assuming head loss is neglible, what is pressure difference between 1 and 2. b) If pressure head...
  30. R

    Venturi and a pin hole in a water pipe

    Dear Experts, I was looking at Venturi effect and a question popped into my mind. When I use a water hose and turn on the tap, the water rushes out of the hose. If there is a break along the hose, eg. a small puncture, some water would also leak through this hole am i right? At least this...
  31. L

    How is the Energy Increasing in a Venturi Experiment?

    Homework Statement Hi I have done an experiment applying the bernoulli equation on a venturi tube, according to bernoulli the energy must remain the same. However according to my calculation the energy increases when the tube contracts up to the point of the throat. Can someone explain how...
  32. S

    Bernoulli's Principle: Venturi Pipe

    1. Where did i go wrong, please explain. Homework Statement The Horizontal Venturi pipe has a cross sectional area of 50cm^2 at the wider portions(A_1) and 25cm^2 at the constriction(A_2). Air density of 1.29 kg/(m^3) is flowing in the pipe. Theres a attachment of a picture to reference...
  33. S

    Solve Vertical Venturi Meter Discharge w/ Mercury & Data

    Homework Statement Considering that water flows in the pipe and mercury is used in the manometer, compute the discharge through the pipe. Please see the attached information for the given data. Homework Equations Bernoulli: (P1/rho * g) + (V1^2/2g) + Z1 = (P2/rho * g) + (V2^2/2g) + Z2...
  34. D

    Bernoulli's principle with venturi effect

    So, I need some info on how to get the data that I'm missing on my project. My english is not great and is very hard for me to try figure this out by myself so if you guys could help me out I will appreciate. I need to know how much vacuum in HG I will get at the B on my picture, and if will...
  35. A

    Measuring Flow Rate in a Pipe with a Venturi Device

    Homework Statement Describe how a venturi device for measuring the flow of water in a pope works and estimate the slowest flow rate such a device could be expected to measure using 20% of cross sectional area constriction and a mercury manometer. Homework Equations A1V1=A2V2 I also know...
  36. T

    Why pressure is lower at the small bore of a venturi

    Hi, why is it that in a venturi system the pressure is lower when the diameter of the cross sectional area is smaller? I do not understand why pressure can be considered a form of "energy". I can understand that energy must be conserved and due to the reduction in the diameter the increase in...
  37. C

    Understanding the Venturi Effect in Fluid Dynamics

    Hi, I have a pretty elementary question, but I'm having trouble finding an adequate explanation on the web. I'm trying to figure out how a carburetor works, and am having difficulty figuring out how a venturi tube works. On the one hand, as air flows through a narrow section of a pipe, it...
  38. H

    Venturi meter/ coefficient of discharge experiment

    Homework Statement [LIST] It was a standard venturi meter experiment where we calculated the theoretical and actual mass flow rates for different pressures and velocity's. the follow up questions were: -Compare the results of the coefficient of discharge obtained with typical values given...
  39. B

    Calculating Pressure Difference in Venturi Meter

    Homework Statement The gauge pressure at the inlet of a horizontal venturi meter is 40kPa. The vacuum at the throat is 38 mm mercury. If a differential U-tube manometer containing mercury is the U-tube and the oil in the connecting tubes is connected to the venturi, what will the difference...
  40. A

    Calculating the suction force produced by a Venturi

    Dear all, As I understand the venturi effect, if a flow of water passes through a constriction, its velocity increases and its pressure decreases at the restriction. The decrease in pressure allows a suction force to be produced. I am trying to use this principle in order to power a vacuum...
  41. M

    How Does Non-Horizontal Orientation Affect Venturi Meter Results?

    What would be the effect on the results if the venturi meter was not horizontal and why? This is research i must complete before I carryout my experiment and lab report?? Help Plz
  42. L

    How Does a Venturi Meter Calculate Fluid Speed Using Bernoulli's Equation?

    1. Find , the speed of the fluid in the left end of the main pipe. Express your answer in terms of h_1, h_2 , g , A_1, A_2. 2. Bernoulli and continuity equations 3. p_1 = rho*gh_1 p_2 = rho*gh_2 p_2 = p_1 + 0.5rho*v_1^2 + 0.5rho*(A_1/A_2)^2 * v_1^2 I know those are...
  43. V

    Fluid motion in venturi flowmeter

    Homework Statement The venturi flowmeter is used to measure the flow rate of water in a solar collector system. The flowmeter is inserted in a pipe with diameter 1.9cm; at the venturi of the flowmeter the diameter is reduced to 0.64cm. The manometer tube contains oil with density 0.82 times...
  44. C

    Boggling result of venturi experiment

    Hi! I'm boggled by the results of my experiment...maybe you can help me... I made an improvised venturi meter which I used to determine for the velocity of water flowing in a pipe. Then just to confirm my velocity value I allowed the water to just gush out of the venturi meter (disconnected on...
  45. Saladsamurai

    Venturi Meter Finding Pressure Difference

    Homework Statement I guess I am having a hard time seeing what that manometer is doing. I assume that as fluid moves in at 1 it causes a displacement of the manometer fluid by some distance h. Now, are we assuming that the pressure is uniform throughout the diameter of the pipe...
  46. G

    Is My Method for Calculating Pressure Difference in a Venturi Meter Correct?

    Homework Statement Water flows through a venturi meter, with an inlet diameter of 25cm and a throat diameter of 15cm. The pressure difference is measured using a manometer, which displaces the mercury by 12mm on the throat side. Homework Equations Bernoulli's Mass continuity P=rho.g.h...
  47. R

    Understanding the Venturi Effect: A Physics Expert's Guide

    Dear Physics experts, I am trying to build a venturi tube. I found some diagrams from the internet. As we know, in the middle of the venturi tube, the pipe is narrower and this is where pressure is lowest and fluid passes through it the fastest. Imagine that this venturi tube is to pass...
  48. S

    Venturi Flow Model: Calculating Air Flow w/ Differential Pressure

    Looking for a good model for calculating air flow through a venturi from the differential pressure. I know about using the Bernoulli equation. What I'm looking for is a reliable method for calculating the correction factors (discharge coefficients, etc)
  49. F

    Venturi Metter - Conceptual Question

    I am working on a lab, and *think* I understand what is going on, but looking for a double check of my logic from someone more experience than I am. In short its a multi-piezometric tube venturi meter, with 1 throat near the begining, a couple of expansions, and a control valve near the end...
  50. K

    Bernoulli's Equation and venturi meter

    Homework Statement A venturi meter is a device for measuring the speed of a fluid within a pipe. The drawing shows a gas flowing at a speed v2 through a horizontal section of pipe whose cross-sectional area A2 = 0.0600 m2. The gas has a density of ρ = 1.60 kg/m3. The Venturi meter has a...
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