Airfoil Average Nusselt Number calculation
 

Hi everyone my current version of ANSYS Fluent is 12.1

The type of flow I am using is a Spalart Allarmaras Model

Please correct me if I am wrong

Now, I wantwant to calculate an average nusselt number from the Solution
so do I just simply click "monitor" -> " Surface Monitor"

Report Type: Integral
Field Variable: Wall Fluxes, Surface Nusselt Number??

and also how do I calculate the Reynolds number of the flow as well ?

Thanks =)

I have the Nusselt Number Distribution around the airfoil

does the Nu Distribution look like that ?

http://i40.photobucket.com/albums/e2...lotgrid100.jpg

and how do I average them ? just add them all and divide by the number of point, n ???

ps: this airfoil is a unit length airfoil

Thanks

Hi,
before computing Nu No., be sure that your reference values are correct.(report->reference values)
I think for evaluating average Nu No., you can compute total heat transfer from airfoil and then obtain an equivalent h(heat transfer coefficient) and then compute Nu.(just a suggestion)

Yes I've checked the reference value are the correct for air properties

as far as obtaining equivalent h from total heat transfer...
what delta temperature should I use ?? ( Temperature varies along the chord length too)

Thanks,

I think it's a good idea to use dT=(Tave-Tinf). you can obtain Tave from report->surface integral->average facet. isn't it?

so what you're saying is:

h_avg = overall_heat_transfer_rate / ( T_avg - T_fluid )

Nu_avg = h_avg * chord_length / k_fluid

correct me if I am wrong

yes, it's right if T_fluid & k_fluid remain constant during solution.