# Problems on aerodynamics

1. Jul 28, 2011

### zahidfcuk

1. The problem statement, all variables and given/known data
A hypersonic experimental aircraft is flying in the lower stratosphere at an altitude of 20 km, at a ground speed of 177m/s.
a)the atmospheric pressure and temperature experienced by the aircraft at 20 km altitude, assuming an isothermal variation in temperature in the stratosphere,calculate
b)the Mach number at which the aircraft is flying.
c)the Mach number behind the shock wave located just ahead of the aircraft nose.
d)the temperature and pressure experienced by the tip of the aircraft nose.
2. Relevant equations
I do not know which one to use. Beginning of the question it says hypersonic, so I am kinda confused whether to use equation on incompressible or compressible.
3. The attempt at a solution

2. Jul 28, 2011

### viscousflow

Why are you confused? The aircraft is hypersonic but it's ground speed is 177 m/s which is Mach 0.183 @20 km far from sonic

3. Jul 29, 2011

### zahidfcuk

wow thank you. I think i just got carried away a little. But still I dunt know my ans are correct or not.

4. Aug 4, 2011

### zahidfcuk

can anyone tell me, where can I get some solved problem in aerodynamics??