Hi Jetpipe
"As you probably are familiar with the bernoulli effect (Pt=Ps+Pd), the distribution of dynamic and static pressure over a moving surface depends on many variables (aoa, airflow angle, camber, material, etc.) f.ex. at the
stagnation point of a wing the dynamic pressure will be 0 and the static equal to Total! So the a/c form can interfere with the ''normal'' airflow and that will cause pressure disturbances, mostly increased static pressure because of the deceleration of the air molecules that come in contact with the airframe . At subsonic speeds the air is thought to be isentropic, meaning that it can adiabatically change state (Kinetic to Potential energy without heating loss and vice versa). At supersonic speeds and above (I think even transonic), the air can not longer be seen as an isentropic, incompressible fluid and that means it will produce an error that will affect Total pressure readings!"
Why can the air no longer be seen as an incompressible fluid at supersonic speeds and how come it starts to lose heat at supersonic speed?