# Is it possible to determine the mass flow rate through the engine of MiG-21 during its various cruise Mach no. operations?

Is it possible to obtain the mass flow through the Tumansky R-25 turbojet engine mounted on a MiG-21 during its various standard operating (cruise) Mach numbers?
Note: standard as in older planes where there were just 3 positions of the inlet cone - upto Mach 1.5, between 1.5-1.9 and above 1.9.

Also, what should be the cruise condition for this plane, given that it is capable of flying at various Mach numbers and thus speeds?

• Just out of curiosity, what is this project you are working on? – Jay Carr Sep 30 '15 at 19:03
• oh it is a homework project :P I suppose assignment would be more appropriate term. – Manish Sep 30 '15 at 19:08
• I wish my homework had been like that...would have probably helped if I'd been doing aeronautical engineering of course... – Jay Carr Sep 30 '15 at 19:19
• Tell me what is given and I can start to answer. Otherwise, just google it ;-) – Peter Kämpf Dec 14 '15 at 14:04

The mass flow is approximately $20 \ldots 100~kg/s$.