Pressure Gradient for Nitrous Flow

[Kevin]

Hello everyone,

I am currently working on an undergraduate club team for the Intercollegiate Rocket Engineering Competition. I am attempting to do a calculation to determine the pressure needed in a vessel leading to another pressurized combustion chamber to achieve a desired mass flow rate.

These are my requirements:

Mass flow rate of Nitrous Oxide: 2 [lbs/sec]
Down stream pressure: 800 [psi]
Tank pressure: ?
Temperature: 308.15 [K]
Tubing Length: 1.3 meters
Tubing Type: Steel Woven PTFE, 3/8" Diameter (but this can change)

Unfortunately my courses have not given my adequate knowledge of fluid flow from one pressurized vessel to another to determine the pressure required. Also if there are any other changes that may thought to be helpful I am very open to suggestions

Thanks for you help!

 

[jaumzaum]

Have you already learned Navier stokes? It’s the key to equation this problem if you know how the friction is. Besides, if you consider the friction to be fully developed, steady and incompressible, the pressure loss can be obtained from de Darcy friction equation:
Pressure loss = $\lambda (l/d_h) \rho v^2/2$

 

[berkeman]

Hello everyone,

I am currently working on an undergraduate club team for the Intercollegiate Rocket Engineering Competition. I am attempting to do a calculation to determine the pressure needed in a vessel leading to another pressurized combustion chamber to achieve a desired mass flow rate.

These are my requirements:

Mass flow rate of Nitrous Oxide: 2 [lbs/sec]
Down stream pressure: 800 [psi]
Tank pressure: ?
Temperature: 308.15 [K]
Tubing Length: 1.3 meters
Tubing Type: Steel Woven PTFE, 3/8" Diameter (but this can change)

Unfortunately my courses have not given my adequate knowledge of fluid flow from one pressurized vessel to another to determine the pressure required. Also if there are any other changes that may thought to be helpful I am very open to suggestions

Thanks for you help!

Sounds like a fun project.

Do you have a Mentor and Safety Officer for this rocket project? Will they be checking your calculations and the responses from the PF?