# increased flowrate decreased in heat rejection?

 User Name Remember Me Password
 Register Blogs Members List Search Today's Posts Mark Forums Read

 April 7, 2010, 21:03 #21 Senior Member   Join Date: Nov 2009 Posts: 125 Rep Power: 8 Hi guys, how are you? This time, i used the model shown in 'pipeTH3.jpg', and only used water to perform CHT. No other temperature BC or convection BC applied. with 3kW heat source, using the heat taken away expression, water is calculated to take away 3315.93W. so, i think i'm still facing the problem of clarification of the results. RMS residuals are below 1e-5, and Domain imbalances are <1%. why is the heat taken away by water still larger than the heat source applied please? __________________ Thank you for your kind attention. Kind regards, mactech001 Currently using: ANSYS v13

 April 7, 2010, 23:34 #22 Member   Dmitry Volkind Join Date: Jan 2010 Location: Chelyabinsk, Russia Posts: 58 Rep Power: 8 Send me Your .def-file, I'll try to run it and see what's wrong. dvolkind@hotmail.com

 April 8, 2010, 07:14 #23 Senior Member   Join Date: Nov 2009 Posts: 125 Rep Power: 8 There's one other enquiry: taking my 1st example in CHT analysis. How can i evaluate the cooling efficiency of my model please? __________________ Thank you for your kind attention. Kind regards, mactech001 Currently using: ANSYS v13

April 12, 2010, 09:34
fluid flow cylindrically=rotating fluid?
#24
Senior Member

Join Date: Nov 2009
Posts: 125
Rep Power: 8
Hi guys,

in this attached picture, cfxOutput.jpg, a simple model that represents the eventual complex geometry. It is a cylindrical model that can accommodate an electrical machine in the inner space. In this cylindrical housing, there is an internal cooling channel with ribs to increase the effective surface area for heat convection. The electrical machine in the housing will have losses. Losses are applied to the model as heat flux. I am trying to obtain a design that is to use water that flows in the channel to take away all the losses. Outer surfaces of the cylindrical housing is air.

Does this fluid that flows in a cylindrical path considered a rotating fluid please?
Attached Images
 cfxOutput.jpg (39.3 KB, 2 views)
__________________
Thank you for your kind attention.

Kind regards,
mactech001
Currently using: ANSYS v13

 April 12, 2010, 13:08 #25 Member   Dmitry Volkind Join Date: Jan 2010 Location: Chelyabinsk, Russia Posts: 58 Rep Power: 8 No it's not a rotating fluid. Why do you ask? By the way, I'll try to make your model work soon. Had no time since your last letter. You also asked about how you should estimate cooling efficiency: in your case I would measure the ratio of electric power needed to pump the cooling water (W) and heat power (kW). For example, 100 W/kW, not 10 %. That's what we usually do in Russia)

 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 GUOQIANGWOO FLUENT 2 April 6, 2010 01:29 enigma Main CFD Forum 2 November 1, 2009 23:53 DG FLUENT 9 December 25, 2008 21:57 Mark CFX 6 November 15, 2004 16:55 azmir CD-adapco 0 June 23, 2004 20:53

All times are GMT -4. The time now is 18:27.

 Contact Us - CFD Online - Top