I'm trying to simulate aerospike nozzle at sea level. From my calculation, I should get ~2.71 exit Mach number but I get reversed flow in pressure inlet. When I use Roe-FDS, I get reversed flow in inlet after several thousands iteration.

Even if I leave the calculation(never converged), the flow doesnt even look like I expect it to be. Not even close.

I can't seem to attach my files. The loading is too long. So I insert it to external download link from WeTransfer instead.

**General:**

Density based

Axisymmetric

**Models:**

Energy

Inviscid

**Material:**

Air

-Ideal gas

-Cp 1006.43 J/kg k

-Molecular weight constant 28.966 kg/kmol

**Boundary condition**

Inlet

-Gauge total pressure 1500000 Pa

-Supersonic gauge pressure 1499999 Pa

-Total temp 900 K

**Outlet**

-Gauge pressure 101325

-Total temp 288 K

**Methods**

Formulation:Implicit

Flux type: AUSM

-Least squares cell based

-2nd order upwind

**Control:**

CFL: 3

The rest is left at default.