ANSYS Fluent Lab

Converging-diverging nozzles (Laval nozzles) are used in various fields such as aerospace, propulsion, and supersonic wind tunnels. They allow a fluid to be accelerated to supersonic speeds by exploiting expansion and shock phenomena. 

1. Generate an automatic structured mesh for the converging-diverging nozzle.

2. Simulate the compressible flow of an ideal gas through the nozzle.

3. Display contour plots of pressure, temperature, velocity, and Mach number.

4. Plot pressure, temperature, velocity, and Mach number curves along the symmetry axis.

5. Validate the simulation results with the quasi-1D theoretical solution.

Using ANSYS Fluent, simulate the flow through the convergent-divergent nozzle, and determine the following:

1. Contours of pressure, temperature, Mach number, and local velocity.

Plot the distribution of pressure, temperature, velocity, and Mach number along the symmetry axis of the nozzle.

Assumptions:

1. The flow is steady and axisymmetric (in r and x axis).

2. The flow is inviscid (since the Reynolds number for this high-speed flow is large, and viscous effects are confined to a small region close to the wall).

3. The flow is compressible, and the gas is considered ideal air.

4. The solution will be compared with the theoretical quasi-1D nozzle flow results.

The plot below compares the Mach number distribution between the quasi-1D theoretical solution and Ansys Fluent simulations with different mesh resolutions. Because the fluid is ideal, the difference between the mesh resolutions is slight, with the variation becoming more noticeable at the outlet of the nozzle. As the mesh resolution increases (from 15x35 to 60x140 nodes), the Fluent simulations more closely match the theoretical solution, demonstrating that higher mesh resolutions have a small but noticeable impact on the accuracy of the simulation results.