Jet Engine Mass Flow Rate calculation

In summary, the conversation discusses methods for finding the air mass flow rate in a jet engine. The use of the thrust/Isp equation and thermodynamic heat balance are suggested as starting points. To accurately calculate the air mass flow rate, information on inlet and outlet conditions is needed. The fuel flow rate and oxygen mass flow rate can also be calculated using specific equations. Additionally, a momentum balance for the control volume can be used to determine the air mass flow rate.
  • #1
vincentryan
29
0
hi
how to find air mass flow rate in jet engine?
we are using thrust/Isp equation to find the mass flow rate for rocket equation. is that any formula available for finding the mass flow rate in jet engine
 
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  • #2
You could start with a simple thermodynamic heat balance to get a ballpark figure.

Do you have any information on the inlet and outlet conditions or intermediate conditions like the compressor outlet to the turbine inlet?

What is the thrust/Isp equation? Can you post it?

Thanks
Matt
 
  • #3
For Rocket,
Total Mass Flow rate W = F (Thrust) / Isp (Specific Impulse)
Fuel Mass Flow Rate Wf = W/(r+1)
Oxygen Mass Flow Rate Wo = W-Wf

r = fuel - oxygen mixture ratio

you have asked information about the inlet and outlet conditions or intermediate conditions like the compressor outlet to the turbine inlet.
Take on example of GE 90 - 110B and GE 90 - 110B1 engine.

the fuel flow rate for jet engine is calculated by the following equations
mfuel = Fuel flow rate=mair(f/a)/(B+1)
f/a=Cpg(To5-To4)/HV

help to fine the air mass flow rate
 

1. How is the mass flow rate of a jet engine calculated?

The mass flow rate of a jet engine is calculated by multiplying the density of the air entering the engine by the velocity of the air and the cross-sectional area of the engine's inlet.

2. What units are used to measure jet engine mass flow rate?

The mass flow rate of a jet engine is typically measured in kilograms per second (kg/s) or pounds per second (lb/s).

3. How does the mass flow rate affect the performance of a jet engine?

The mass flow rate is a critical factor in determining the thrust and power output of a jet engine. A higher mass flow rate results in more fuel being burned and thus generates more thrust for the engine.

4. What factors can affect the mass flow rate of a jet engine?

The mass flow rate of a jet engine can be affected by the engine's design, operating conditions, and altitude. Changes in air density, temperature, and pressure can also impact the mass flow rate.

5. Why is it important to accurately calculate the mass flow rate of a jet engine?

Accurate mass flow rate calculation is crucial for the safety and efficiency of a jet engine. It ensures that the engine is receiving the correct amount of air and fuel to produce the desired thrust and power output. Any miscalculation can lead to engine failure or reduced performance.

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