Hello,

My name is Edwin Guerrero and I am an aerospace engineering student. I am having difficulty with simulating my rocket nozzle, particularly, the residual plots for my simulation will not converge, as in, they will not plummet down to below my convergence criteria. Also, it may be related to this problem, my velocity contours look very strange? The velocity seems to be increasing again when approaching the outlet. Below are photos of my simulation and residual plots.

I have simulated other similar rocket engine nozzles and they perfectly expand the exhaust gases to be axially. Below, are some key parameters of my simulation:

**General**:

- Type: Density-based
- 2D Space: Planar

**Models:**

- Energy: On
- Viscous Model: k-epsilon; realizable

**Materials:**

- Fluid: (solid-fuel-one)
- Density: ideal gas
- Cp: 1881.15 j/kg-k
- Thermal Conductivity: 0.0242 w/m-k
- Viscosity: sutherland
- Molecular Weight: 23.77 kg/kmol

**Boundary Conditions:**

- Inlet: pressure-inlet

- Gauge Total Pressure: 3447378.64 Pa
- Supersonic/Inital Gauge Pressure: 3447368.64 Pa
- Total Temp: 2603.15 k

- Outlet: pressure-outlet
- Gauge Pressure: 10 Pa
- Backflow Total Temp: 288 k

- control volume walls & nozzle walls: wall

**Reference Values**

- Density (kg/m^3): 1667.73
- Pressure: pressure-inlet gauge total pressure
- Temp: pressure-inlet total temp
- Ratio of Specific Heats: 1.2284

My ansys workbench file is attached to this post.