# How to determine the number of compression stages given a compression ratio?

I have a personal project to design a gas turbine engine, the main problem that puzzles me is how do I determine the pressure rise in each stage of an axial compressor?

Say, I'm planning on a 38:1 engine so how do I determine how many stages I might need and how much will be the pressure rise?

• Are we super sure this is not class work? Sounds like class work. How did you select 38:1? What is the application? – acpilot Jun 24 '20 at 17:42
• Just multiply the compression ratio of each stage. It's not so hard – the hard part is achieving those compression ratios at each stage. – Peter Kämpf Jun 24 '20 at 18:11
• @PeterKämpf I think the OP has a total compression ratio and is looking to divide it by the number of compressor in the engine to determine pressure rise/compressor. As a matter of fact, that may just be the answer he's looking for... – FreeMan Jun 24 '20 at 18:35
• @FreeMan: I know, and all he needs now is a realistic stage compression ratio. But he should now do a bit research himself. – Peter Kämpf Jun 24 '20 at 18:52
• @acpilot: Couldn't agree more. With 38:1 the T4 will be too high for some amateur engine. You need mono crystalline blades with film cooling – impossible to do in a personal project. – Peter Kämpf Jun 24 '20 at 18:55