Mass flow rate Definition and 89 Threads

What is velocity V in mass flow rate formula, velocity of inlet ,outlet, velocity of rocket speed in relation to freestream?

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...

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?

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...

Working out as follows x= (20-6)/20 = 0.7 Fk = k / air specific heat ratio Fk = 1.31/1.4 Fk = 0.94 xT = Fk * x 0.94 x 0.7 = 0.658 because xT < x = 0.658<0.7 flow through the valve is choked Expansion factor Y Y = 1 - x/( 3 x Fk x xT ) Y= 1- 0.7/( 3 x 0.94 x 0.658) Y = 0.623...

Im trying to do some past exam papers. If i can get help with the method on how to solve and have correct formulas, it will help me. I) There is one formula in the notes to get mass flow rate: Heat lost by steam = Heat taken up by water GsHfg = (GwCpw)(change in temp) Gs x 2748 x 10x103 =...

how can i convert mass flow rate into molar flow rate using density of the gas.

Could anyone kindly kind me as to where this formula is derived from and how, because I searched and can't find it anywhere

Lets say if I have a pipe with one end closed, and drill a small hole on the side of the pipe near the closed end. Then I use vacuum at the open end to create mass flow exiting the pipe. Where is the opposite force on the pipe? [crackpot youtube video deleted by moderator @russ_watters ]

Hello everyone, Can the mass flow rate of air by a propeller connected to an engine through a small tube change if the rpm of the propeller is increased?

Hello, Can you tell me please the mass flow rate of hydrogen and oxygen per unit of area of electrodes in fuel cells? Or if you have information on the mass flow rate of hydrogen and air per volume of fuel cell stack? I understand this may vary, but I am looking for publications or other...

Hey, I'm a student who has to complete a written assignment for physics. I chose to launch water rockets and investigate the effect of volume on the range. I am trying to also come up with a mathematical model however I am struggling to understand an equation I found the following equation to...

I'm having a brain storm, If I have an 8 cylinder 4 stroke engine running at 4000 rpm over a 10 minute test and it consumes 4.4 Kg of fuel, then is the fuel mass flow rate as simple as the 4.4 Kg divided by the time to give me an answer on Kg/sec ? Thanks,

Hi, wondered if anyone can give me a pointer on this problem I am working on. 6 Diesel engines each with power 55kW running, given output cooling water temperature of 80°C, and required return temp of 60°C. The coolant is to be fed through a heat exchanger, with the heat exchanger outlet to be...

Hello all, Looking for ideas on how to calculate mass flow rate from a velocity contour plot. The cross-sectional area is circular. An example of the velocity contour plot is shown in the figure below: In most of the cases (as exemplified above) the flow is non-axisymmetric. Any suggestions...

Hello all, I have an in-house designed flow meter with roughly the configuration in the figure. In the setup, a restriction is placed in the flow stream (the rows of horizontal lines in the figure). Pressure measurements upstream and downstream of the restriction, P1 and P2, respectively are...

< Mentor Note -- thread moved to HH from the technical physics forums, so no HH Template is shown >[/color] Hey, For our project we have to think of an experiment that can kind of simulate a rocket. We decided to use a fire extinguisher on a kart, since its mass constantly changes (same with a...

This seems simple, but I have some confusion. I'm trying to refine a numerical simulation to get away from my isothermal assumption, to account instead for isentropic temperature and pressure changes in pressure tank with an orifice. Given an insulating air tank of volume ##V##, containing air...

Hello, I want to find the mass flow rate of flue gas, i have only the diameter of pipe and ID fan speed which are 1.48Meter and 980 RPM respectively

Hi When I was writting my thesis I found in an article, published in International Journal of Heat and Mass Transfer, an unit of mass flow rate G - kg/(m^2*s). Isn´t it wrong? I think that the unit of mass flow rate is kg/s. Would you mind helping me to figure it out? Thanks.

Homework Statement If 5% of the heat available for steam production is lost to the atmosphere, determine the amount of steam raised per hour when the total flow of flue gases is 1400 kmol h-1. qmH = 1400 kmol h-1 Flue gas temperatures: Inlet = 1832°C Outlet = 300°C Water temperature: Inlet...

Hi, I am not science student. Can anyone help me to solve this? Density and velocity of a fluid is given as 920kg/m3 and 5m/s, this fluid is flowing through an area of 25cm2. Calculate the mass flow rate? I am in search of some easy unite conversion tricks also.

How to convert volumetric flow rate to mass flow rate?

Hey, I'm working on a project to build a drone which is powered through air jets. The drone needs a valve control system which can control the flow rate (hence the thrust) going to each nozzle in order to adjust it's altitude and stabilty. I need to set up a circuit which can electronically...

Hey, I have an air tank that is at a set pressure, say 3000psi, and I have attached a regulator to the end that regulates the pressure down to 800psi. As the valve on the tank is opened the pressure and the mass in the container will decrease. If there was no regulator the mass flow rate would...

Hi, We have a canister at a set pressure (4500psi) full of compressed air. A single stage pressure regulator is fitted to the canister that reduces the outlet pressure to 850psi. The flow from the regulator is then used in a divergent nozzle to create a thrust force capable of lifting a small...

Hello, I am working with the mass flow rate equation which is:$$\frac{d \dot{m}}{dt}=\dot{m}_{in}-\dot{m}_{out}$$ To determine the change of the height of water in a reservoir. Assuming m_in = 10 and m_out = sqrt(20h), then : $$\frac{d (\rho \cdot Q) }{dt}=\rho \cdot Q_{in} - \rho\cdot...

Good afternoon all, I am doing some back of napkin calcs for work and am having trouble finding an answer (or one that I can understand--its been a while since undergrad). We have a valve that has particular flow rate requirements to prevent unseating the valve seal. This is a mass flow rate...

Hi i have calculated compressor , combustor , turbine inlet and outlet temperature , pressure so on and my output of gas turbine is 50MW , So for this i want to calculate the mass flow rate of air and fuel in compressor , combustor , turbine . Like m0=?,m1=?fan inlet,m2=? compressor inlet,m3=...

Hey, Suppose you have an enclosed vessel that is full of water. You heat it up then you open a valve, and that will create enough thrust for it to act as a rocket. How much energy is needed for a steam rocket to get heated enough to achieve a mass flow rate of 2430 Kg/s. Mass of water= 256...

Hi everyone I searched about the mass flow rates and temperatures of exhaust gases of light gasoline internal combustion engine at different condition but I don't fond anything yet . Anyone can guide me? .

Hi, First-timer here! I'm designing a physics project that involves pumping a certain pressure of air into an empty bottle. SETUP: The bottom of the bottle has a small hole through which a thumb tack fits tightly; the top (cap-side) has a valve through which the air is inserted. The bottle is...

Homework Statement An turbine expands air at 1300 kPa and 500oC to 100 kPa and 127oC. Air enters the turbine through a 0.2-m2 opening with an average velocity of 50 m/s, and exhausts through a 1-m2 opening. Determine (a) the mass flow rate of air through the turbine Homework Equations PV=RT m...

Hello everyone, i am currently dimensioning a compression system using a vehicle turbocharger and need to find a way to relate the pressure ratio of the compressor and the mass flow rate. (flows trough compressor and turbine are of course separated) For the turbine, one can use Stodola's...

Hi, I used a blower to flow air across an open duct through a nozzle. By using a gate valve, the mass flow rates were controlled. I took measurement in 3 different locations along the ducts. But, why by decreasing the mass flow rate, the air velocity was increased? It is just happened for the...

Homework Statement A patient, on an anesthetic, is hooked up with only 18 mg of the anesthetic remaining. If the current flow is 12 mg/h and the dentist needs to increase the flow to 20.0 mg/h within two minutes, then how long will it take for the anesthetic to run out? Homework Equations...

I know that F=ma which give the units of kg.m/s/s (in SI units) but can force also be expressed as mass flow rate times velocity which also has the same units? Example: water coming out a hose or gas coming out a spray can?

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...

I have a condenser with a mass flow rate of 60kg/s, an initial point 1: P=50kPa, Quality = 95% and a final point 2: P = 50kPa that is saturated liquid. cooling water flows through the condenser with a mass flow rate of m(dot) and has a delta temperature of 15 degrees Celsius. how do i...

I've Attached the question and my answer to question 1 to task 3 and guidance if I've done it right? Or any guidance?

Does the mass flow rate differ depending on whether it's after the feedwater heaters or before the turbines or is it just constant throughout the entire system?

Hello there, so I have answered my question from fluid systems but the answer doesn't look right ;/ and I have no idea what have I done wrong. Can you please check and correct where it's wrong ? ;) here is the question: A pipe contains a gradually tapering section in which its diameter decreases...

I am confused about the relation of mass flow rate with different mach numbers in a compressible flow. In wikipedia (http://en.wikipedia.org/wiki/Choked_flow), I read the following: "Although the gas velocity reaches a maximum and becomes choked, the mass flow rate is not choked. The mass flow...

I am interested in mass flow rate in conveyor screw transportation http://www.colormaxsystems.com/wp-content/uploads/2013/11/5-screws-300x222.jpg any recommended book,engineering guides ?

I need create a math model to predict the temperature of a copper pipe with hot air flowing through based on the temperature of the air, properties of the air and copper, and the surface area of contact between the air and the pipe. The pipe will start cold but I will be looking to the...

I have a pipe with regular diameter connected to a tap, the water comes from public supply, I assume that public supply can vary on pressure and flow rate. How can I guarantee that I allways get the same volumetric flow rate at the end of the pipe? Will a pressure reducer be sufficient? Thank you!

I would like to install a vent stone on a 3/4" vent line. The line vents upwards of 1500 psig of stored gasous nitrogen in under 1 second. The vent stones are only rated for 300 psig, so I'd like to add an orifice just upstream to limit the exit flow rate to a point where it can handle the...

Homework Statement 1. An emergency vent line from a reactor is 55 feet long and has an inside diameter of 4.026 inches. The surface roughness of the pipe is 0.0012 inches. The line discharges hydrogen to the atmosphere (P = 14.7 psia) a) If the mass flow rate of hydrogen is 95 lb / minute...

How do you calculate the mass flow rate, volume flow rate and velocity of a 6 bar compressed air supply through a 2mm tube? This is all the information I have been given. Is there any theory that could help me here? I can't seem to find much on the internet, so I have no clue where to begin...

Homework Statement Work out the mass flow rate of Nitrogen traveling through a at 0.3m^3/s if the pressure is 1 bar and the temperature is 18°C and the ideal gas constant is 8314 J/Kg K Homework Equations m=ρ*V*A m = mass flow rate ρ= density V = velocity A = flow area PV =...