Transient Simulation, wall placed at inlet/outlet

jeettrivedi · July 19, 2017, 04:17

Im doing a simulation of an intake plenum with inlet and initialization pressure as 101325 Pa. outlet is a function of seconds vs mass flow in kg/s

when the inlet valve is open mass flow is positive and hence i have no trouble but when the mass flow is negative due to the valve closing. i get an notice that a wall has been placed at inlet and outlet and depending on the value it says some % of area is blocked.

I Believe this is done to prevent reverse flow. when this persists for multiple timesteps cfx gives a return code of 1 and the run ends with no results .

Note : in my geometry only the plenum and runner is modelled. values of mass flow are realistic ranginf from 0.03 to 0.18 kg/s . modeled as SST

-Maxim- · July 19, 2017, 07:10

have you read the FAQ?
https://www.cfd-online.com/Wiki/Ansy...f_an_OUTLET.22

Post pictures of your setup and post the full error message (out-file) so that we can help you properly

July 19, 2017, 04:17	Transient Simulation, wall placed at inlet/outlet	#1
jeettrivedi New Member Jeet Join Date: Jul 2017 Posts: 1 Rep Power: 0	Im doing a simulation of an intake plenum with inlet and initialization pressure as 101325 Pa. outlet is a function of seconds vs mass flow in kg/s when the inlet valve is open mass flow is positive and hence i have no trouble but when the mass flow is negative due to the valve closing. i get an notice that a wall has been placed at inlet and outlet and depending on the value it says some % of area is blocked. I Believe this is done to prevent reverse flow. when this persists for multiple timesteps cfx gives a return code of 1 and the run ends with no results . Note : in my geometry only the plenum and runner is modelled. values of mass flow are realistic ranginf from 0.03 to 0.18 kg/s . modeled as SST

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July 19, 2017, 07:10		#2
-Maxim- Senior Member Maxim Join Date: Aug 2015 Location: Germany Posts: 413 Rep Power: 13	have you read the FAQ? https://www.cfd-online.com/Wiki/Ansy...f_an_OUTLET.22 Post pictures of your setup and post the full error message (out-file) so that we can help you properly