Prandtl–Meyer function
In aerodynamics, the Prandtl–Meyer function describes the angle through which a flow turns isentropically from sonic velocity to a Mach number greater than 1. The maximum angle through which a sonic flow can be turned around a convex corner is calculated for M =. For an ideal gas, it is expressed as follows,
where is the Prandtl–Meyer function, is the Mach number of the flow and is the ratio of the specific heat capacities.
By convention, the constant of integration is selected such that
As Mach number varies from 1 to, takes values from 0 to, where
where, is the absolute value of the angle through which the flow turns, is the flow Mach number and the suffixes "1" and "2" denote the initial and final conditions respectively.
