What is Volumetric flow rate: Definition and 30 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.
I'm using two tanks of nitrogen and oxygen and mixing them in different ratios to change the oxygen partial pressure in the system. System is opened to the atmosphere through the venting pipe which therefore sets the total pressure of the system to 1 bar. System is opened and gases flow through...
Hello all,
I'm having trouble figuring out the volumetric flow rate upstream of a relieving pressure regulator used on a 1/4" OD nitrogen line. Upstream of the regulator P=100 PSIG and T=70F, while downstream P=80 PSIG and T=70F with downstream consumption at q=4 L/min or 0.91 SCFM (at std...
Hi, I have designed a simple Venturi meter to measure pressure differential across to section of the pipe as pictured. However in calculations I am not sure if I am doing something wrong. I am trying to calculate Volumetric flow rate in L/s.
I am using Bernoulli Equation of the Venturi meter as...
Hi. I am currently doing my internship in the oil and gas industry (contractor) as process engineer. My supervisor give me a task to do some reverse engineering where i need to study how a spreadsheet (calculation) construct by other process engineer was been constructed. Ok the situation is the...
Hello kind people of PF
I am looking to mount a fan on one end of a pipe but I'm not sure how much air can the pipe transfer. (Volumetric flow rate)
The pipe is vertical and 15 meters long.It has a diameter of 10 cm. I'm looking to push air from top to bottom using a fan.
Need to know the...
a) so Q=V/t = Av
Q is constant ( same At A0 and A). That means I have to find the velocity of the water either at A0 or at A. But how can I find it? I thought there must be a reason that h is given but the only way I can use it is to assume the velocity is 0m/s at A0 but actually it is not...
Hello everybody,
This is my first post. I've been working on a liquid rocket engine for a while, but I have never gotten to work on its feed system (fluid mechanics), until recently. We are using a very simple pressure fed system, and its main goal is to deliver the propellants at a specific...
Hi pf,
I have a reaction ## aA → bB ## in a PFR reactor. The simplest equation to write is:
## \frac {dF_A} {dV} = -R ## where ##F## is the Molar flow rate. ##F = C_A*Q## where ##Q## is the volumetric flow rate and ##C_A## is the molar concentration of A.
My textbooks says that if ##a=b##...
I'm trying to learn more about how air compressors work (not how they mechanically function - how they're input/out pressures and flow rates work) and I'm having a lot of trouble getting a specific questioned answered even after a lot of google searching.
Suppose I have a compressor that the...
Homework Statement
Air is to be compressed from a pressure of 1 bar and a temperature of
20°C to a pressure of 15 bar in a two stage compressor with intercooling.
After intercooling the air temperature returns to 20°C and the polytropic
index of compression is 1.28. If the input power per...
1. Homework Statement
Hi. This is a problem related to designing a RC hover craft. We are given a datasheet for a fan used as thrust.
http://imgur.com/6liZSid Sorry image post no working, url: http://imgur.com/a/6XLwL
We have to approximate the equation to a straight line through the curve...
Homework Statement
Imagine that you are blowing air through a straw in a cup of water and the root of the straw was connected through a rectangular box with empty base and every side of the rectangular box was cut into "teeth" shape. Bubbles will come out from the teeth of the rectangular box...
Hi guys, quick simple question.
Lets say I have a pipe separated into 3 sectoins (all horizontal), all have the same flow areas.
In the first section it is all liquid water. I know the mass flow rate in this.
In the second section the water is heated. And I can work out the steam quality...
Homework Statement
A hose with a nozzle 80 mm in diameter ejects a horizontal stream of water at a reate of 0.044 m3 s-1. With what velocity will the water leave the nozzle? What will be the force exerted on a vertical wall situated close to the nozzle and at right-angles to the stream of...
How to calculate how much flowrate from blower i can push water pool 2,75m*1,8m down by 1,25m in 1 sec?
Note : Blower Pressure 0.03 bar - 0.035 bar
There is an empty room above the water pool with dimension of 2.75m*1.8m*1.7m
This process happen in a closed chamber...
Hello everyone,
I am quite new to Fluid dynamics, so I would like to ask for your help.
Is it possible to calculate volumetric flow rate from the instantaneous pressure?
We need to know the flow rate of the air entering the cylinder in the engine due to the suction pressure. It is required to...
Homework Statement
Hello, I have really hard time to express the gas law PV=nRT to PQ=ṁRT where Q is volumetric flow rate and ṁ- mass flow rate.
Is it possible ?
Teacher told me, it is ...
Homework EquationsThe Attempt at a Solution
I'm new here, and I have a question that might be easy but really confuses me.
Does the volumetric flow rate of incompressible fluid change across a valve?. Based on my analysis, no it can not change since the mass is conserved, and since it's incompressible fluid. I know that the velocity will...
With a given 2kW pump
That pumps a liquid with a density of 820kg/m³ from one tank to another that's 30m higher.
With a calculated change in pressure to be 241.3kpa.
Find the volumetric flow rate.
I feel like there are not enough given variables for this problem. What do you think?
My chemical engineering is a little rusty after 25 years and I could use a little help with this real world problem. This isn't my project but I've been asked to advise. Sorry for the limited information.
We have a 30 gallon tank with 75% hydrogen/25% nitrogen mixture at 100 psig. From the...
Hi everyone, I'm currently a mechanical engineer interning at an HVAC company. I need to measure the resistance of a fluid through ductwork. The CFD shows a linear curve through a plenum when plotting R vs volumetric flow rate. For example, a straight rectangular box 1 1/16” by 2.5” and 3ft...
Hey, I was wondering how to calculate the volumetric flow rate (Q) of a liquid other than water through a hole at the bottom of a tank.
I know that
Q= V.A
and
1/2.ρ.V^2 = ρ.g.h
Where,
V: Velocity of the liquid coming out of the hole
A: Area of the hole
h: Height of the...
Hi all,
I am stuck on a problem, and it's been a while since I took fluid dynamics. I have a cylindrical tank of know capacity with an inlet, where a vent is attached, and an outlet, the fluid gets sucked. The tank has fluid in there with known volume and density. If I know the usage rate of...
I'm not sure how to clearly express my query, so I'll round up the gist of it. I understand that this is an entry level question.
I was told that, in order to calculate Volume Flow Rate (VFR), I would use these equations:
* Q = Velocity * Area [EQUATION 1]
* Q = Volume / Time [EQUATION 2]...
I posted this in the DE forum as well since it is related.
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Hi all,
I've got a fairly straight forward problem to solve here regarding flow rate out of a tank with uniform cross-sectional area. I am treating this is a volumetric flow problem since there is assumed...
At atmospheric pressure of 14.2 psi, if I had a 1 ft square hole through a 5 foot thick wall into an endless space vacuum, I am trying to find out the the final maximum volumetric flow rate that our atmospheric pressure would push air through the hole.
I tried using Poiseuille's Equation...
hi ,
I have a question that if you answer it I would be so thankfull, Q is:
"Can we calculate volumetric flow rate without knowing cross-sectional area?
If,yes,How?"
I have this Q because I see a portable Thermometer,volumetric flow rate meter ,which show it without giving any area size...