Hello.
I need to evaluate the nusselt number for Nu=4.36 for constant heat flux case.
My hand calculations give the Nu number at the exit gives Nu=4.36 but I'd like to evaluate properties like, the local Nu number or the local heat transfer coefficient etc..
Can anyone briefly guide me how to do it in COMSOL?
I know there are a lot of people struggle to find it but there is no brief answer for that.
Thanks
Hey John Riley ,
You may follow these...
https://www.comsol.com/blogs/calculating-the-heat-transfer-coefficient-for-flat-and-corrugated-plates
https://www.comsol.com/model/nonisothermal-laminar-flow-in-a-circular-tube-55861
https://doc.comsol.com/5.3/doc/com.comsol.help.pipe/PipeFlowModuleUsersGuide.pdf
Best wishes.
Hello John Riley
Did you create the setup?
In which part are you having problems?
Do you need help with setting it up or obtaining the results?
Mohammad Rahjoo the presentations that Gautam . . shared helped me out to find the local Nusselt number. Last thing is, if you can tell me how to find the mean Nu number. I provided the formula.
I go with the derived values, line integration on the wall, and write
(qw/(T-Tb))/L where qw is the heat flux on the wall, T is the temperature on the wall, and Tb is the bulk temperature of the system. This gives me the average heat transfer coefficient as 2.38 for the problem specified by Gautam . . (Compute surface integral is not selected)
Then I put h_mean into Nu_avg=h_mean*D/k where D is the pipe diameter in this case and that gives me the average Nu number.
Is this correct?
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