Convergent-Divergent Nozzle: 3-D

Description

This module uses ANSYS Fluent to simulate compressible flow through a 3D convergent-divergent nozzle, a fundamental problem in compressible flow modeling and high-speed propulsion applications. The simulation examines shock wave formation, Mach number evolution, and boundary layer behavior as flow accelerates from subsonic to supersonic conditions through the nozzle throat and divergent section.

Methodology

The nozzle geometry is analyzed under compressible flow conditions, resolving the transonic transition at the throat and the resulting supersonic flow field in the divergent section. Shock wave development is captured and visualized, along with its effects on pressure, temperature, and velocity. Boundary layer behavior along the nozzle walls is modeled under compressible conditions, including interactions between the boundary layer and shock waves, and flow separation regions in the divergent section are identified using CFD-based prediction methods.

Conclusion

Results include Mach number distributions showing the subsonic-to-supersonic transition, pressure and temperature profiles across shock regions (including deviations from ideal isentropic behavior due to friction and heat transfer), and flow separation zones affecting nozzle performance. Nozzle efficiency metrics such as thrust coefficient and specific impulse are calculated, and parametric studies support nozzle geometry optimization. These findings apply directly to rocket propulsion system design and supersonic wind tunnel development.