Compressible Flow Subroutine Library
Programming Reference Manual
Version 1.0 DD-00008-110E

3.10.1 Introduction

These functions compute the thermodynamic properties across a normal shock wave, assuming a calorically perfect gas and an adiabatic and frictionless flow, as described in [naca1135]. It can compute the following set of properties given one of the properties in conjunction with a specific heat ratio γ of the gas medium.

The following equations govern normal shock waves as implemented in the function group:
Equation of Mass

p1u1 =p2u2

Equation of Momentum

p1+ ρ1u21=p2 +ρ2u22

Equation of Energy

1u21+h1 = 1 u22+h2 [adiab]
2        2

Normal Shock Waves are classified by the following properties, where the subscript 1,2  refers to upstream and downstream, respectively.

The following properties are computed:

Table 8: Normal shock properties



I Property Description



1 M1n Upstream mach number
2 M2n Downstream mach number
3 p2/p1   Pressure ratio
4 ρ /ρ
 2 1   Density ratio
5 T2/T1   Temperature ratio
6 p02/p01   Stagnation pressure ratio