Supersonic Drag

As the Mach number increases further, the drag associated with compressibility continues to increase. For most commercial aircraft this limits the economically feasible speed. If one is willing to pay the price for the drag associated with shock waves, one can increase the flight speed to Mach numbers for which the above analysis is not appropriate.

In supersonic flow an aircraft has lift and volume-dependent wave drag in addition to the viscous friction and vortex drag terms:

This approximate expression was derived by R.T. Jones, Sears, and Haack for the minimum drag of a supersonic body with fixed lift, span, length, and volume.

The expression holds for low aspect ratio surfaces. Notice that unlike the subsonic case, the supersonic drag depends strongly on the airplane length, l. This section describes some of the approaches to computing supersonic wave drag components including:

Wave Drag Due to Volume

Wave Drag Due to Lift

Program for Computing Wing Wave Drag