ESDU AERO 00.03.05 gives expressions for the variation with the ratio of pressure to stagnation pressure of the following ratios: the temperature to the stagnation temperature@ the density to the stagnation density@ the velocity to the speed of sound and the velocity to the speed of sound at stagnation conditions@ and provides graphs of the functions. The ratio of specific heat capacities is taken as 1.4 and the air is assumed to behave as a perfect gas.