Secondary Injection Thrust Vector Control - SITVC

amirh.ja · June 20, 2014, 02:47

hi every one
i simulate Secondary Injection Thrust Vector Control with plume. my simulation run but my residual such as U and V after few iteration start oscillation from 10^-2__10^-3

.
i use a pressure for inlet to nozzle and injection and use a opening boundary condition for plume.
please help me
tanks

hmasenger · June 20, 2014, 02:58

i think it would be better to move the opening BC farther from current location.phsical time scales whould also effect your convergence.

ghorrocks · June 21, 2014, 05:58

This is an FAQ: http://www.cfd-online.com/Wiki/Ansys...gence_criteria

And Hamed is right, your outlet opening probably is too close.

vlad · January 16, 2015, 11:11

above posts are right your outlet should be downstream at least 7 times your nozzle exit diameter. Also meshing close to secondary injection and nozzle lip is important; Your injection nozzle should be long enogh to correctly develop the secondary flow and refined in the vicinity of injection port.

ghorrocks · January 18, 2015, 05:57

Be careful with recommendations like "should be downstream 7 times the nozzle exit diameter". This may be correct for a certain class of flow but it is rarely generally correct. The best way to approach it is to do a sensitivity study on your particular configuration and find out exactly what is needed for your flow.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Diesel injection problem	Jurek	FLUENT	2	June 16, 2017 06:05
injection problem	Mark New	FLUENT	0	August 4, 2013 01:30
jou file command for the injection!	asal	FLUENT	0	June 4, 2013 04:15
SITVC calculation	cfdzak	Main CFD Forum	0	July 18, 2012 02:50
Thrust value, positive or negative?	Emmanuel	FLUENT	0	June 25, 2007 19:47

June 20, 2014, 02:58		#2
hmasenger Senior Member hamed Join Date: Apr 2009 Posts: 148 Rep Power: 17	i think it would be better to move the opening BC farther from current location.phsical time scales whould also effect your convergence.

June 21, 2014, 05:58		#3
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	This is an FAQ: http://www.cfd-online.com/Wiki/Ansys...gence_criteria And Hamed is right, your outlet opening probably is too close.

January 16, 2015, 11:11		#4
vlad New Member Vladeta Join Date: May 2009 Location: BGD Posts: 5 Rep Power: 16	above posts are right your outlet should be downstream at least 7 times your nozzle exit diameter. Also meshing close to secondary injection and nozzle lip is important; Your injection nozzle should be long enogh to correctly develop the secondary flow and refined in the vicinity of injection port.

January 18, 2015, 05:57		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,703 Rep Power: 143	Be careful with recommendations like "should be downstream 7 times the nozzle exit diameter". This may be correct for a certain class of flow but it is rarely generally correct. The best way to approach it is to do a sensitivity study on your particular configuration and find out exactly what is needed for your flow.