# 2 boundary conditions at one interface?

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

 April 23, 2008, 15:27 2 boundary conditions at one interface? #1 YY Guest   Posts: n/a Hi guys, I want to specify my inlet with a static pressure and a flow rate. Is that possible? Thanks.

 April 24, 2008, 04:06 Re: 2 boundary conditions at one interface? #2 Subha Guest   Posts: n/a Hai, Yes it is possible. After setting the inlet boundary with static pressure, click on the Sources Tab and there you could give a Total Source under Contnuity. Could you explain why you need such a boudary? Regards, Subha.

 April 24, 2008, 07:32 Re: 2 boundary conditions at one interface? #3 Rogerio Fernandes Brito Guest   Posts: n/a Can I use, for ex., heat flux [W m^-2] and temperature [K]constant on the same boundary contourn (boundary condition)? How come?

 April 24, 2008, 07:58 Re: 2 boundary conditions at one interface? #4 Andrew Guest   Posts: n/a Why do you want to set the heat flux and the temperature at the wall? That boundary condition would explicitly define the fluid temperature at the wall.

 April 24, 2008, 11:31 Re: 2 boundary conditions at one interface? #5 YY Guest   Posts: n/a Hi, Thanks for your reply. I need it because I'm trying to mimic this FSI simulation where the flow rate and pressure is defined. Because if I were to use just the pressure I could not get the flow I want and vice versa. I also tried using total pressure but to no avail. So I guess I'll try what you have suggested. Thanks again. Really appreciate it. Regards, YY

 April 24, 2008, 14:49 Re: 2 boundary conditions at one interface? #6 Rui Guest   Posts: n/a But that Total Source won't be equal to the flow rate. If you have an Inlet with P1 and an Outlet with P2 (P1>P2), without any mass source (Source=0), you'll have a flow rate (different to zero), right?

 April 25, 2008, 02:12 Re: 2 boundary conditions at one interface? #7 YY Guest   Posts: n/a Hi, I have tried using the source option but the results are not what I want. I'm basically modelling flow in a circular pipe. I would like to set a Reynolds number and a static pressure at the inlet. Any advice guys? How exactly do you use the source option. I'm very confused. Thanks people. Regards, Yi Yong

 April 25, 2008, 07:43 Re: 2 boundary conditions at one interface? #8 Andrew Guest   Posts: n/a What is your outlet condition? Specifying pressure at the inlet and the outlet is typically avoided. If you want to set the pressure at the inlet, you can set the mass flow at the outlet to get the desired Reynolds number. Note that if you set the pressure at the inlet and outlet and also specify the mass flow at the inlet, your system is overdetermined and will not converge, even if the mass flow and pressure conditions are taken from real measurements.

 April 25, 2008, 11:54 Re: 2 boundary conditions at one interface? #9 YY Guest   Posts: n/a hey, My outlet is just a 0 static pressure outlet. Yea I would think so too. Haven't done a CFD specifying 2 b.c's at one place but apparently the PHD thesis which i'm following, the person applied a velocity and pressure at the inlet. Regards, Yi Yong

 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 kestasposkus CFX 28 July 24, 2011 06:47 Pankaj CFX 9 November 23, 2009 05:05 mactech001 CFX 6 November 15, 2009 22:25 michele OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 2 July 15, 2005 04:15 lego CFX 3 November 5, 2002 21:09

All times are GMT -4. The time now is 23:14.