Steady-state-steady-flow of a compressible gas. A thin normal shock occurs
and is shown for a control volume fixed on the wave. Relative flow at (1) approaches the shock
from upstream and uniform relative flow at (2) movies away downstream of the shock. For this
flow situation only the pressures and densities are known. The gas is not thermally perfect.
Starting from 1st principles develop the following general relationship for the shock speed of
a wave moving into a static fluid. This is the shock speed (left-right) viewed from the ground.
Fig: 1