linearized supersonic flow on airfoils
 

as we know,linearized potential flow on supersonic airfoils predicts wave drag. in linearized potential flow perturbations are so small that will be no shock wave and all will be mach wave and so process will be isentropic. so how does linearzied theory can predic drag due to shock wave that are related to nonisentropic process).

Re: linearized supersonic flow on airfoils
 

Simply put it doesn't predict the drag due to the shock. The wave-drag is the drag due to the small amplitude acoustic waves radiating away from the aerofoil,

Tom.