What is Flow rate: Definition and 495 Discussions

In physics and engineering, in particular fluid dynamics, the volumetric flow rate (also known as volume flow rate, rate of fluid flow, or volume velocity) is the volume of fluid which passes per unit time; usually it is represented by the symbol Q (sometimes V̇). The SI unit is cubic metres per second (m3/s). Another unit used is standard cubic centimetres per minute (SCCM).
In hydrometry, it is known as discharge.
In US customary units and imperial units, volumetric flow rate is often expressed as cubic feet per second (ft3/s) or gallons per minute (either US or imperial definitions).
Volumetric flow rate should not be confused with volumetric flux, as defined by Darcy's law and represented by the symbol q, with units of m3/(m2·s), that is, m·s−1. The integration of a flux over an area gives the volumetric flow rate.

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  1. A

    Fluid Mechanics - Need Help on a Water Pipeline Project

    My current pipeline is open ended on each side meaning I raise water level in a creek to create natural flow to the inlet and the outlet discharges from my pipe directly into a surface ditch. The surface ditch is well cleaned so that the top of the pipe is above water level at discharge meaning...
  2. N

    Effect of pressure due to change in diameter of pipe

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  3. M

    Flow rate of air through constriction

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  4. mahdis

    Flow rate experiment not producing same results as the Hagen-Poiseuille law?

    I have repeated the experiment several times and it always shows my longer length has the fastest flow rate. the same results occur when I apply 300mmH pressure to the fluid bag on top, the flow rate is still faster in the longer pipe
  5. alexlsu

    Flow rate needed to lift object inside a vertical pipe

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  6. mahdis

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  7. L

    Calculating flow rate when emptying liquid from a closed-top tank

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  8. M

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  9. J

    Calculating Output Pressure for 15L N2/min

    Hello, i’m not good in physics so I came here for help. I have a high pressured gas tank (200 bars) and a flow rate regulator. I need to release 15L of nitrogen per minute, but my regulator only measures output pressure between 0 and 400 bars (0 - 6000 psi). How do I measure the output pressure...
  10. tracker890 Source h

    Question about source flow rate across line AB.

    Q:Please hlep me to understand which ans is correct.To determine the flow rate in Line AB. $$\mathrm{Known}:V_A,q,r_A = constant.$$ so/ select:## A,{B}^{\text{'}},B,A,## is control volume $${Q}_{AB}={Q}_{A{B}^{\text{'}}}=\iint _{A}^{}({V}_{A})dA={\int }_{{\theta }_{A}}^{{\theta...
  11. tracker890 Source h

    Question about flow rate in the source flow

    Please help me to understand what wrong with method 2. ref.Flowrate Between Streamlines (Thank you for your time and consideration.)
  12. B

    I Flow rate calculation of coating application

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  13. blinkz303

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  14. RealityMechanics

    Determining Reverse Mass Flow Rate Formula for Multiple Diameter Tubes

    Alright, this is more of a conceptual question than a HW question that will nonetheless help me design something. In the attached image, air is flowing through a large area tube and then a small area tube from right to left. A collaborator previously figured out the equation for measuring the...
  15. A

    Inconsistent flow rate measurements of an engine diesel fuel

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  16. P

    I Calculate the internal pressure of a tube based on flow rate

    I have pump of unknown flowrate pumping water through a tube of length L and diameter D. I know that the flowrate of water exiting the tube is X mL/min. I would like to know the internal pressure of the tubing, how can I calculate it? This all occurs at sea level elevation.
  17. O

    Engineering Mass flow rate as a function of time

    At first, I inputted h(t), of which I solved for, into the mass flow rate formula. So it looked something like this, m-dot(t) = -(density)*[sqrt(g*(H-(g*d^4*t^2/D^4)]*(pi/4)*d^2 But I don't think that's right? Any thoughts?
  18. A

    Coolant Mass Flow Rate Through Subchannel in Nuclear Fuel Assembly

    I am trying to find the mass flow rate of coolant through a channel within a hexagonal nuclear fuel assembly. I am given the specific heat of the fluid, the coolant inlet and outlet temperatures, the total power produced by a single fuel pin, the diameter of the fuel pin, the length of the fuel...
  19. C

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    Hello, I am working on a project that involves air at high pressure and temperature flowing through an orifice (valve) from one container to another. For each container, the volume, temperatures and pressures are known. The valve diameter is also known, and the fluid is air (which can be...
  20. Ophi-Siren-Kit

    Speed/Velocity and Volume Flow Rate of Viscous Fluids

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  21. D

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    Our system of interest has a duct on the left and a piston chamber on the right that make the shape of the letter T rotated 90º clockwise. The smaller tube on the left is abbreviated as P1 has an unspecified length while the piston chamber is P2. The air in P2 heats up and expands while the...
  22. R

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  23. N

    How Do You Calculate the Flow Rate of Oxygen in a Pressurized System?

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  24. Edwardminett

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  25. C

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  26. H

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    I performed an experiment where I let water flow out of a measuring cylinder through a hole at the base of the measuring cylinder. I let the water run out for 30s, recording the volume after. I did this for different heights of water in the measuring cylinder, and kept the pressure of water at...
  27. DaveC426913

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  28. C

    Calculate flow rate in a tap and the height of a reservoir

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  29. F

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  30. G

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  31. F

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  32. Teeg

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  33. B

    Volume Flow Rate: Open vs Closed Valves

    Made an attempt at this Q but I'm unsure on how to do part c) or if I had even done part a) and b) right What difference does it make to the volume flow rate equation when the valve goes from open to closed? Any help would be appreciated! Thanks
  34. A

    Flow rate of a pipe - calculation

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  35. Amirul96

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  36. Geith

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  37. Anon_Miner

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  38. WhiteWolf98

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  39. S

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  40. V

    How can the molar flow rate of a two-gas mixture be calculated?

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  41. V

    Convert Mass Flow Rate to Molar Flow Rate

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  42. X

    Measure flow rate with a manometer (pressure gauge)

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  43. R

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  44. areamer02

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  45. T

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  46. harishree90

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  47. Izazo

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  48. T

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  49. men5j2s

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