Question

Problem 2.3. An ideal ramjet is to fly at 20,000 ft with a Mach number of 3.5. The burner exit total temperature is to be 3200 °?? and the engine will use 145 lbm/s of air. The heating value of the fuel is 18,500 Btu/lbm. What is the diameter of the rounded exit, thrust, dimensionless thrust, and TSFC at this condition?

(Assume that the temperature is 447.38°??, the static pressure is 6.747161 psia, and the specific heat ratio is 1.4 at 20,000 ft. The gas constant (R) is 53.35 ft ·lbf/(lbm·°R). The specific heat (Cp) is 0.2399565 BTU/(lbm·°R). The unit conversions are as follows: 1 lbf=1 slug·ft/s2, 1 slug=32.17 lbm, 1 ft=12 in, and 1 BTU=778.16 slug·ft2/s2.)

Answer 1