Incompressible & Compressible Aerodynamics

A scramjet engine features an intake, isolator, combustor, and a nozzle, as shown in the schematic. Station 3 indicates the combustor entry point. Assume stagnation enthalpy to be constant between Stations 1 and 3, and air to be a calorically perfect gas with specific heat ratio γ. Select the correct expression for Mach number M3 at the inlet to the combustor from the options given.

Options:

• (A) 3 3 2 1 1 TMM T   =-  - 
• (B) 2 3 3 21 1112 TMM T       -  = + -  -   
• (C) 3 3 TMM T  =
• (D) 2 3 3 1 112 TMM T    += - -  