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-   -   How to simulate traneisnt gas flow between 2 contaiuners connected using a nozzle? (https://www.cfd-online.com/Forums/fluent/203509-how-simulate-traneisnt-gas-flow-between-2-contaiuners-connected-using-nozzle.html)

nav.shirur@gmail.com June 29, 2018 09:07

How to simulate traneisnt gas flow between 2 contaiuners connected using a nozzle?
 
Hello community,


My problem is as follows,


A nozzle is connceted between 2 gas containers with 1000 bar pressure difference. I want to simulate gas flow from high pressure to low pressure container and plot the pressure, velocity, density Mach number till equilibrium is reached. Could anybody provide info on how to setup model in Fluent? I know basic Fluent simulation but Tank filling and draining i am unable to setup.



Regards
Naveen

LuckyTran June 29, 2018 11:51

The basics are the same. You just need to run a transient simulation with the right equation of state (e.g. ideal gas). You set the initial condition for each tank to desired values (pressure, temperature, density, etc.). The initial velocity is of course 0. There is some learning here on how to set different initial values in different parts of the domain. This can be done though using the patch button and carefully constructing cell registers to patch different parts of the domain.

nav.shirur@gmail.com June 29, 2018 12:39

Fleuent transient simulation
 
Many thank for the reply. I tried it, but i am facing few problems,
Details: Pressure difference 1000 bar
standard initilization + implicit formulation (Dint work)
Convergent nozzle

I tried to just model the flow initially without the tanks, it works good when i use hybrid initilization + explicit formulation. It doesnt work for standard initilization + implicit combination.
After this i tried to model transient as stated in the thread, here i am facing following problems,

1. Most literature suggest using standard initilization but when i do so, i dont see barrel shock which i am supposed to see because it is a convergent nozzle.
2. It says temperature is limited
3. Doesnt work for implicit+standard initilization

Ansys manual says implicit works for shocks as well but explicit is preferred. Could u please through some light on these issues or else could u please provide me your mail id i can send problem and model details?

Many thanks in advance

regards
Naveen

LuckyTran June 29, 2018 13:28

You did all that in a few hours? Impressive...

nav.shirur@gmail.com June 29, 2018 13:34

Fleuent transient simulation
 
Well, i consulted few colleagues as well and it is critical for me i googled and searched youtube. Could reach to that level, and since its is part of my PhD work i had to. No success though. I said i know basic fluent not an expert to know all parameters.


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