Heat Transfer Coefficient
 

Hello,

I'm simulating a usual CHT problem with conduction threw solid. It's a ribbed channel where air flow through.

The solid is heated with constant heat flux . I'm trying to validate this case with experimental data.

However I got different results for the HTC. Could you explain what way I should go for calculating HTC?

Firstly I've analysed the implemented methods of Starccm+ (Spec. Y+ HTC, HTC) and I'm aware of the different methods that the software is using for reference temperature.

But I'm not sure if it is possible to calculate the HTC by analysing the boundary heat flux,Wall Temperature and the bulk Temperature of the local area by my own using HTC=q_w/ (T_w-T_ref).

For example at a specific surface point I got a value of 66 for the implemented HTC calculation method and a value of 58 for the specified Y+ HTC method. By calculating HTC via boundary heat flux,wall temperature and bulk temperature I got a value of 39 which is closest to the experimental data.

Do you know why I get such a big difference between the implemented HTC coefficient methods of the software and my own HTC calculation ?

In addition there must be mentioned that I've taken boundary heat flux and Wall Temperature by analysing the closest point in the Solid/Fluid-Interface at the nearest cell to the IF.

Thank you for your help.