Question

estion 9- Ramjet Operation (15 Points): You are asked to calculate the operational parameters of an ideal ramjet engine. flame holder combustion zone Me inlet diffuser nozzle e- Nozzle exit throat-M-1 Normal shock wave Ramjet 3-Burner exit 2- Diffuser exit 00 K. Flight altitude is 10 knm Flight Mach number is 2.0. Burner exit temperature is 17 Make the following assumptions: Assume that the Mach number in the combustor is zero (stations 2 and 3) Ignore pressure losses in the combustor (P2- P3) .Flow in the diffuser and nozzle are isentropic (not through the shock wave though!) Assume ideal gas and calorically perfect gas. Perfect nozzle (exit pressure is matched to the atmospheric pressure) a) Calculate the nozzle entrance (burner exit) pressure. b) Calculate the nozzle exit velocity.

Answer 1

Answer

1. Nozzle entrance pressure

(Pa) (Pa)

1.4 12211.4/1.4-1 22)1-4/14-1)

  

0.41351(1.8)3.5

2 3.2354kg/rm

2. Nozzle exit velocity

Ve 2.52V 1.4 * .287 * 1700
((T_oe / T_a) = $(1+\frac{\gamma -1}{2}Me^{2})$ ) $\approx$ M_e = 2.52

   m/s

1455