The wave-drag coefficient is a dimensionless quantity that measures the drag due to shock waves on a body moving at supersonic or hypersonic speeds. It is defined as the ratio of the wave drag force to the dynamic pressure times the reference area of the body. The wave-drag coefficient depends on the shape, size, and angle of attack of the body, as well as the Mach number and the properties of the flow. For some simple geometries, such as a flat plate or a diamond airfoil, the wave-drag coefficient can be calculated analytically using the shock-expansion theory, which applies the conservation laws across oblique shocks and expansion waves on the body surface.
- Wave-drag coefficient (cd)
- Angle of attack (𝛼) in rad