Supersonic Jet Ramped Intake CFD Simulation Training

Description

Supersonic Jet Ramped Intake Simulation, ANSYS Fluent CFD Training

In this project, we have simulated a supersonic jet ramped inlet using ANSYS Fluent software. With the development of jet engines and the subsequent ability of aircraft to travel at supersonic speeds, it was necessary to design inlets to provide the flow required by the engine over a wide operating envelope and to provide air with a high-pressure recovery and low distortion.

These designs became more complex as aircraft speeds increased to Mach 3.0 and Mach 3.2, design points for the XB-70 and SR-71, respectively. The inlet is part of the fuselage or part of the nacelle.

The ramped or angled intakes are designed so that the angled surfaces form the shock waves, and the uniform and undisturbed flow enters the channel and the engine. The geometry of the cross-section changes as it moves along the channel to give shape to the flow.

In this case, it is modeled from an Intek with a ramp, and its model is taken from the geometry of the F-15 Intak. And this inlet is placed in a supersonic flow with a speed of Mach 1.4, and the changes in speed and pressure and the speed profile along the channel are investigated.

The present model in the 3-D domain of this simulation has been designed in ANSYS Design Modeler. The part contains a velocity inlet, pressure outlet, and wall for the intake wall and side for the far field.

The meshing of this present model has been generated by ANSYS Meshing software. The mesh grid is unstructured; the total cell number is 1278343 elements.

Methodology

In this simulation, the density-based solver has been used. For modeling turbulence, the k-omega SST model was used. In this simulation, the intake is simulated at the operational point with a velocity of 1.4 mach.

Supersonic Jet Ramped Intake Conclusion

In the simulation results, according to the Mach number contour, it is clear how oblique waves and expansion fans are formed in the intake and inside the intake channel.

These shock waves at the beginning of the air inlet make the flow speed subsonic and make the flow uniform, and inside the channel, it acts like a converging and diverging nozzle. It is also evident in the performance of the pressure and temperature contours and how it affects them.

For a more detailed analysis, we look at the speed contours in different intake areas and find out how this wall form has made the flow speed uniform along it.

The pressure contour along the range also shows how the intake opening pressure drops and then recovers during it. This causes the engine to remain in ideal working condition and not suffer from compressor stall.