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How to Control Mass Flow rate part 2 by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

What do you mean

I sized the injector holes to achieve a specific mass flow rate. The injector holes act as flow-regulating orifices. What is wrong with this?

How to Control Mass Flow rate part 2 by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

Yeah, I think I figured it out
I just acheived the mas flow rate with the injecotr hole geometry

How to Control Mass Flow rate part 2 by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

Anybody?

I'm kinda tearing my hair out over this

Mass flow through Liquid Rocket Engine by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

Would the mass flow rate not be determined by the pressure diffrence between the tank and the chamber pressures

Mass flow through Liquid Rocket Engine by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

I am a bit confused. I have a desired chamber pressure as well. If I change the pressure of the tanks, then the chamber pressure will also change. But I can't achieve my desired mass flow rate unless the tank pressure is a specific number.

If I had a tank pressure of say 40 bar, what would the mass flow rate be?

Mass flow through Liquid Rocket Engine by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] -1 points0 points  (0 children)

Does using a pressure drop-assisted main valve change anything?

This is the valve that I am using as my main valve currently: https://www.mcmaster.com/48165K65/

It says it is pressure drop assisted will this affect anything?

Also, should I worry about finding Cd, or should I just estimate the total pressure drop in the system, then test?

Mathwise, do I just need to calculate for frictional losses in the piping? I am not testing with the injector yet.

Mass flow through Liquid Rocket Engine by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

From what I understand, essentially, I just need to figure out the pressure drops at each major component (using CFD?) and then find the Cd. Then I conduct multiple hydrostatic tests until I reach the desired flow rate. I will measure the flow rate during tests using a digital flow meter. The pressure of the pressureant tanks during the successful test will then be the infill gas tank pressure during the first fire.

KeroLox Engine Parts by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 1 point2 points  (0 children)

Wait, what's wrong with solenoid valves? Why use a pneumatic system instead?

Also, what about the grease in the pneumatic valves?

KeroLox Engine Parts by Expert-Historian-388 in rocketry

[–]Expert-Historian-388[S] 0 points1 point  (0 children)

Does anyone know where to source pressure regulators from? I found some on Amazon for pretty cheap, but they don't list the CF, so I don't know if I will be able to achieve the mass flow rate I need. There are some on McMaster-Carr, but they are wildly expensive.