C-D nozzle supersonic jet boundary
 

Hi,everybody,

I am trying to simulate the supersonic jet of a CD nozzle. What I know now is the inlet total pressure, total temperature and the nozzle geometry. My solve method is to simulate from nozzle inlet to outside part of the jet. So I make a 2-D domain including nozzle and a rectangular area of 10 times in high and 30 times of the nozzle exit size.

1. my problems is how to set the rectangle part boundary? the rectangle surface normal to the jet was set to pressure-outlet and the nozzle inlet was set as pressure-inlet. but I don't know how to deal with the up and boundary surface of the rectangle.

2. Second problems of mine is the shock caputure. I expected that I can catch at least 5-6 shocks in the distance of 2 times of the nozzle exit, but I can only get 1 or 2 from the results.

Anyone who can help me? thank you. any answer will be welcome.

Re: C-D nozzle supersonic jet boundary
 

Hi, Upper part should be wall!

I suggest you to solve the problem using the 1D-Isentropic relations to have a apriori knowlege of the flow field. This will help you even in detemining the BC since the shock wava location is depending on the exit pressure.

Regards, Jim

Re: C-D nozzle supersonic jet boundary
 

Hi,

At Exit go for Extended domain, Give Atmospheric condition at the extended surfaces.

I hope this will solve your problem.

Bye aero

Re: C-D nozzle supersonic jet boundary
 

Thanks a lot for your kind answer jim and aero.

Now my problem is that I can't understand how can I define the up and bottom boudary of the extend domain out of the nozzle exit.

Someone tell me the up and bottom boundary can be defined as symmety. I tried, it is helpful. But I still can not understand why should I do this.

Looking for qualified freelancer to simulate supersonic flow through C-D nozzle using fluent 6.2.16

please contact upal_arif@yahoo.com