Sizing radial combustion chambers "Help if you can"

[aero]

Hello,



I'm currently working on my graduation project, which involves designing a microjet engine. This is my second post seeking assistance. I've encountered a problem in designing the combustion chamber. I've already developed MATLAB code to size the combustion chamber, but I'm facing difficulty in determining the appropriate sizing for the holes in the primary zone, secondary zone, and dilution zone. Our combustion chamber will be radial, and we plan to utilize a centrifugal compressor. I would greatly appreciate any assistance with this matter. If you require access to the code, I'd be happy to share it with you or arrange a voice call to discuss how to approach this issue. Despite my efforts to search online, I've found that many equations are not clearly defined. I'll include a picture of what I've developed so far.

[racket]

Hi

Have you worked out your vapourising tubes yet , the number of them will determine the number of holes at each Zone as the air needs to not impact the tubes .

Total tube bore area needs to be ~1/3rd of the Primary zone allocation , the total surface area needs to be ~6 times inducer area

For small engines , 12 tubes would be appropriate .

Cheers
John

[racket]

I just had a bit more of a read of your pics...... and I'm confused :-(

What Paper are you basing your calcs on ??

[aero]

Paper title : Rashid Slaheldinn Elhaj Mohammed Design and Analysis of Annular Combustion Chamber for a Micro Turbojet Engine

Link :::https://zenodo.org/record/2643908/files/10010246.pdf

[racket]

You mentioned that your combustion chamber will be...... "radial" ............??

Please explain your overall design , just a quick sketch will do

[racket]

Maybe have a look at this www.researchgate.net/publication/347628833_Design_and_Analysis_of_Annular_Combustion_Chamber_for_a_Micro_Turbojet_Engine

Its for a much larger engine but it'll give you a bit more info