Normal Shock Wave

Definition

A Normal Shock Wave is a shock wave that is perpendicular to the direction of flow. It involves a sudden, nearly discontinuous change in fluid properties (pressure, temperature, density) across a thin region, accompanied by an increase in entropy.

Characteristics

• Occurs only in supersonic flow ($M > 1$).
• Flow becomes subsonic downstream ($M_2 < 1$).
• Stagnation pressure decreases.

Relationships

• Related: Mach Number, Entropy