CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Running, Solving & CFD

fan driven flow, Fan BC validation (getting lost)

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

LinkBack Thread Tools Search this Thread Display Modes
Old   July 7, 2013, 19:16
Default fan driven flow, Fan BC validation (getting lost)
New Member
soonic's Avatar
Join Date: Apr 2010
Location: Brno, Czech Republic
Posts: 24
Rep Power: 16
soonic is on a distinguished road
Send a message via ICQ to soonic Send a message via AIM to soonic Send a message via Skype™ to soonic

I would like to use a fan in my simulation. There is a TJunction tutorial for pimpleFoam. I simplified it a little more as a straight duct with fan in the middle. I set the pressure BCs to zero to get the flow through the pipe which is driven by the fan not by the pressure difference on BCs. Finally I get no flow throught the pipe.
I tried few simple cases on straight duct with no luck to get flow driven by a fan. I wish to have the flow based on pressure drop of the ducting-network, which will set the velocity of the flow based on fan characteristics. That is how I imagine the fan should work in real and computationaly too.

There are few questions I have got.

a) How the fan BC works ? Since I am not qualified enough to read source code, I found only a thread there on the forum where is a description, but I cannot get wanted results based on fan characteristics described in a f parameter for pressure jump and velocity as pj=f1+f2*Un.

b) Which of pressures p or p_rgh I should set as fan boundary type to get correct results in case i would like to solve heat transfer with buoyantSimpleFoam? Is the pressure jump relative in units in that case ?

c) I have read about fanPressure BC, but I cannot get correct results also in my testing cases.

d) Is the calculation sensitive to initial conditions ? As I will imagine how could the pressure change through the calculation since the velocity and pressure are tied in cyclic BC through the fan characteristics.

Could anyone post me a case where the fan works as demanded ? The best would be the fan datasheet or any analytical assumption on flow rate and pressure drop which was counted in, with the setting of the simulation.

Thanks for interest and comments
soonic is offline   Reply With Quote


fan fanpressure heat

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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 Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
problem about pressure driven flow yhaomin2007 OpenFOAM Running, Solving & CFD 8 June 4, 2021 07:51
Simulation of Axial Fan Flow using A Momentum Source Subdomain Liam CFX 28 July 16, 2013 08:24
Air flow simulation in volume with fan and opening koziymf FLUENT 0 November 14, 2011 17:44
How to simulate the fan driven by the airflow? Jason FLUENT 2 April 17, 2008 15:56
Question about flow in ducted fan in another duct Jane FLUENT 0 June 21, 2004 13:57

All times are GMT -4. The time now is 19:15.