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Converging-diverging nozzle

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Old   July 13, 2018, 12:55
Default Converging-diverging nozzle
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So I'm new to Fluent and I'm trying to do a simulation of a Converging-diverging nozzle. For starts, I'm considering inviscid flow. I'm supposed to obtain a supersonic flow downstream the throat followed by a normal shock. However, I can't seem to achive these two phenomena. I think I'm messing something up setting the BC.

Here's what's given:
* Mach number inlet: Ma= 0.239543
* Stactic pressure inlet: p_s_inlet=1 bar=10^5 Pa
* Stactic pressure outlet: p_s_exit =0.83049*p_s_inlet
* Total temperature inlet: 300 K

I calculated the total inlet pressure using the Mach number and pressure relation. Set the Operating Pressure to 0, so I can work with absolute pressures. Here's what my inlet and outlet BC look like:

Pressure Inlet:
Pressure Outlet:

I'm working with air as an ideal gas. I set the inlet BC to Pressure Inlet because of compressibility.

So, any ideas why I can't get to the results I need? Do you guys see anything wrong with the BC?

I fully appreciate and look forward to your replies. Thanks in advance.

Note: if imgur hosting is not appropriate I can change it. Sorry for anything.

UPDATE: here are the contours of Mach numbers for the simulation with the BC above. It's converged in 2015 iterations.
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Old   July 13, 2018, 19:12
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Is the throat area small enough to choke the flow?
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Old   July 14, 2018, 06:08
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Behrooz Jamshidi
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This is not a CFD problem. First of all your flow needs to be choked. Choked flow is independent of geometry. For air as working fluid, your discharge pressure must be less than 0.53*Pinlet. While you set discharge pressure as 0.83* Pinlet, it is obvious that you can not get choked flow and subsequently shock.
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