cfd analysis of fan

jyotinkateshia · January 23, 2014, 04:26

I am working with cfd analysis as my project work.In my project i have to analysis of FAN placed inside a close room,No inlet condition inside room and fan is rotating at 2000 RPM.which type of boundary condition should i use?
should i write UDF ? can it be done with the use of dynamic mesh ?
please kindly help me..

flotus1 · January 23, 2014, 05:06

First of all, you should make up your mind about what you want to simulate.

If it is the flow through the fan itself with all the details of its geometry, then at least a sliding mesh is needed.

If it is the air flow inside the room caused by the fan, then there are simpler simulation approaches that dont require modeling the fan with all the difficulties that come with it.

jyotinkateshia · January 23, 2014, 07:56

I have to do analysis of air flow inside the room caused by fan..Then which type of boundary condition should i use ?

flotus1 · January 23, 2014, 08:52

Fluent has a fan boundary condition for this specific purpose. The manual has all the information you need about it, including an example of how to use it.

jyotinkateshia · January 23, 2014, 11:16

In fan boundary condition how to calculate pressure jump?
and how swirl velocity specification should given ?

flotus1 · January 23, 2014, 11:44

That depends on the fan you are using.

For the pressure difference, the manufacturer should have a chart "pressure jump versus flow rate" just like this one on the last page:
http://img.ebmpapst.com/products/dat...3212JH-GER.pdf

Concerning the swirl component, I would leave it zero as long as you dont have any specific information.

jyotinkateshia · January 24, 2014, 07:58

Thank you..for the help..but how can i cfd analysis of air flow inside the room caused by fan along with rotating fan in animation.

flotus1 · January 24, 2014, 08:18

If you absolutely need the rotating fan to show-off, you will have to model it.
You might aswell do some advanced post-processing to add a rotating fan to the simulation results, but I have no idea how to do that and personally dont like such kind of "blending".

Be aware that most probably, the time scales of the flow inside the room will be several orders of magnitude slower than the time scales of the fan rotating at 2000rpm.
Such a simulation would take a tremendous amount of time, while the benefit of simulating the "real" fan will be quite small.
In fact, the results might even be worse because of the additional difficulties involved in such a simulation.

jyotinkateshia · January 24, 2014, 13:15

can the analysis done by fan boundary condition ? if i want animate rotating fan at 2000rpm ?

January 23, 2014, 04:26	cfd analysis of fan	#1
jyotinkateshia New Member KATESHIA JYOTIN ASHOK Join Date: Oct 2013 Posts: 6 Rep Power: 13	I am working with cfd analysis as my project work.In my project i have to analysis of FAN placed inside a close room,No inlet condition inside room and fan is rotating at 2000 RPM.which type of boundary condition should i use? should i write UDF ? can it be done with the use of dynamic mesh ? please kindly help me..

January 23, 2014, 05:06		#2
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,427 Rep Power: 49	First of all, you should make up your mind about what you want to simulate. If it is the flow through the fan itself with all the details of its geometry, then at least a sliding mesh is needed. If it is the air flow inside the room caused by the fan, then there are simpler simulation approaches that dont require modeling the fan with all the difficulties that come with it. jyotinkateshia likes this.

January 23, 2014, 11:44		#6
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,427 Rep Power: 49	That depends on the fan you are using. For the pressure difference, the manufacturer should have a chart "pressure jump versus flow rate" just like this one on the last page: http://img.ebmpapst.com/products/dat...3212JH-GER.pdf Concerning the swirl component, I would leave it zero as long as you dont have any specific information. WhiteB likes this.

January 24, 2014, 13:15		#9
jyotinkateshia New Member KATESHIA JYOTIN ASHOK Join Date: Oct 2013 Posts: 6 Rep Power: 13	can the analysis done by fan boundary condition ? if i want animate rotating fan at 2000rpm ? Last edited by jyotinkateshia; January 26, 2014 at 09:20.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
confusion regarding geometry for CFD analysis	jeph91	Main CFD Forum	2	June 22, 2013 17:33
CFD analysis assistance required	clementlsy	Main CFD Forum	5	June 3, 2013 04:32
Verifying fan test results with CFD	Jenny	FLUENT	0	January 17, 2006 01:52
Where do we go from here? CFD in 2001	John C. Chien	Main CFD Forum	36	January 24, 2001 22:10
part-time-cfd	Michael	Main CFD Forum	6	February 2, 2000 13:01

January 23, 2014, 07:56		#3
jyotinkateshia New Member KATESHIA JYOTIN ASHOK Join Date: Oct 2013 Posts: 6 Rep Power: 13	I have to do analysis of air flow inside the room caused by fan..Then which type of boundary condition should i use ?

January 23, 2014, 08:52		#4
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,427 Rep Power: 49	Fluent has a fan boundary condition for this specific purpose. The manual has all the information you need about it, including an example of how to use it.

January 23, 2014, 11:16		#5
jyotinkateshia New Member KATESHIA JYOTIN ASHOK Join Date: Oct 2013 Posts: 6 Rep Power: 13	In fan boundary condition how to calculate pressure jump? and how swirl velocity specification should given ?

January 24, 2014, 07:58		#7
jyotinkateshia New Member KATESHIA JYOTIN ASHOK Join Date: Oct 2013 Posts: 6 Rep Power: 13	Thank you..for the help..but how can i cfd analysis of air flow inside the room caused by fan along with rotating fan in animation.

January 24, 2014, 08:18		#8
flotus1 Super Moderator Alex Join Date: Jun 2012 Location: Germany Posts: 3,427 Rep Power: 49	If you absolutely need the rotating fan to show-off, you will have to model it. You might aswell do some advanced post-processing to add a rotating fan to the simulation results, but I have no idea how to do that and personally dont like such kind of "blending". Be aware that most probably, the time scales of the flow inside the room will be several orders of magnitude slower than the time scales of the fan rotating at 2000rpm. Such a simulation would take a tremendous amount of time, while the benefit of simulating the "real" fan will be quite small. In fact, the results might even be worse because of the additional difficulties involved in such a simulation.