Problem: Convergent- Divergent Nozzle Venting to Atmosphere

JohnPeclet · January 12, 2015, 08:57

Hi Everyone

This problem is regarding flow through a C-D nozzle. The geometry that is being used is in the attached image. The nozzle is usually given "Pressure Inlet" & "Pressure Outlet" boundary conditions. However, when considering a case where the nozzle flow is allowed to exit into an ambient fluid, what are the boundary conditions that might be required.

Could "Pressure far-field" be used in the external region. I have tried using it and am presented with quite a few errors.

Are there any alternatives that I have not tried yet?

Domain Image : http://i.imgur.com/CfW0tEX.jpg

ramidalf · January 12, 2015, 14:44

You have a a closed volume and there is air under pressure. So, zero pressure condition did not work? Basicly it is only condition you have, pressure = atmospheric pressure at the outlet.

ramidalf · January 13, 2015, 19:57

The set up itself looks very simple. If you want you can send it to me and I will run on my mashine.

January 12, 2015, 08:57	Problem: Convergent- Divergent Nozzle Venting to Atmosphere	#1
JohnPeclet New Member Join Date: Jan 2015 Posts: 2 Rep Power: 0	Hi Everyone This problem is regarding flow through a C-D nozzle. The geometry that is being used is in the attached image. The nozzle is usually given "Pressure Inlet" & "Pressure Outlet" boundary conditions. However, when considering a case where the nozzle flow is allowed to exit into an ambient fluid, what are the boundary conditions that might be required. Could "Pressure far-field" be used in the external region. I have tried using it and am presented with quite a few errors. Are there any alternatives that I have not tried yet? Domain Image : http://i.imgur.com/CfW0tEX.jpg

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Rocket Nozzle problem	Jeremie	FLUENT	10	October 8, 2014 07:16
For Nozzle fluent problem	Jie	FLUENT	17	January 11, 2012 14:44
Convergent nozzle and preesure of steam	pranabjyoti	CFX	7	March 10, 2011 20:23
Nozzle flow problem	prabhu	CFX	2	March 10, 2007 08:38
Convergence Problem Supersonic Flow Laval Nozzle	Tobias	CFX	3	December 7, 2005 02:23

January 12, 2015, 14:44		#2
ramidalf New Member Rami Dalf Join Date: Jan 2015 Posts: 3 Rep Power: 11	You have a a closed volume and there is air under pressure. So, zero pressure condition did not work? Basicly it is only condition you have, pressure = atmospheric pressure at the outlet.

January 13, 2015, 19:57		#3
ramidalf New Member Rami Dalf Join Date: Jan 2015 Posts: 3 Rep Power: 11	The set up itself looks very simple. If you want you can send it to me and I will run on my mashine.