Supersonic Nozzle Flow: Separation and Shock Wave

Description

This module uses ANSYS Fluent to simulate supersonic nozzle flow, focusing on flow separation and shock wave formation — an advanced compressible flow problem central to mechanical and aerospace propulsion engineering. The simulation examines how a converging-diverging nozzle accelerates flow from subsonic to supersonic conditions, and how shock waves and boundary layer separation develop under varying back pressure conditions.

Methodology

The compressible flow governing equations are solved with a turbulence model suited to supersonic conditions, accounting for shock-turbulence interaction. The simulation captures normal shock waves as well as oblique shock structures in overexpanded nozzle operation, and models boundary layer behavior and separation onset under adverse pressure gradients. Nozzle performance is evaluated across a range of back pressure conditions, from overexpanded to underexpanded regimes, including flow-pattern hysteresis as back pressure varies.

Conclusion

Results include Mach number contours showing the subsonic-to-supersonic transition and flow acceleration, pressure and temperature distributions across shock regions, and thrust coefficient and nozzle efficiency calculations under design and off-design conditions. Shock structures, including shock diamonds, are visualized to assess nozzle behavior in detail. These findings support nozzle contour optimization for applications in rocket engine design, supersonic wind tunnel development, and high-speed aerospace propulsion systems.