Modeling transient negative pressure (suction pressure) in outlet

 Register Blogs Members List Search Today's Posts Mark Forums Read

 July 18, 2013, 14:18 Modeling transient negative pressure (suction pressure) in outlet #1 New Member   Join Date: Jul 2013 Posts: 1 Rep Power: 0 Hello, I am new in fluent. I a modeling the two branches system of pipes with two inlets and one outlet. The sucking pressure(negative pressure) is applied in outlet to force the fluid to flow from inlet. This pressure is transient and varies by time. Also, it is important to have a constant mass flow rate which is known form outside. Both inside have the same condition. The system is incompressible. I have some question related to boundary condition: I applied mass flow rate for inlet (we have to get constant mass flow rate from outlet, so I divided this constant number by two, because we have two inlets and put it as mass flow inlet for each inlets) Also, I assigned the pressure outlet which is the profile(user defined profile) as a function of time. As I read in fluent articles, the mass flow inlet is more for compressible flow, so should I change it to any other boundary? I do not have any other information for inlet. Also, for pressure outlet, I have profile of pressure, (not equation), I mean that I have the values of pressure versus time. I got these values from experimental results. These values are negative, should I apply the negative value on the profile or I have to change it to the positive value? I appreciate if you can help me.

 July 18, 2013, 20:59 #2 Senior Member   Join Date: Aug 2011 Posts: 315 Rep Power: 11 For incompressible flow, the pressure difference matters so that you do not have to change the negative values into positive ones. You could use the velocity inlet b.c. instead of mass flow because the former is more robust. May I ask what is the purpose of your simulation? To find the pressure at the inlet?

 Thread Tools Display Modes Linear Mode

 Posting Rules You may not post new threads You may not post replies You may not post attachments You may not edit your posts BB code is On Smilies are On [IMG] code is On HTML code is OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post engahmed Main CFD Forum 0 June 13, 2010 15:34 engahmed FLUENT 0 June 13, 2010 15:33 Abhi Main CFD Forum 12 July 8, 2002 09:11 HB &DS CFX 0 January 9, 2000 14:19 DS & HB Main CFD Forum 0 January 8, 2000 16:00

All times are GMT -4. The time now is 13:40.