How can I compute the heat transfer coefficient in CFD-Post?
In CFD-Post, under File->Export, export Temperature and Heat Flux to a .csv file using the desired surface on which you want to calculate the HTC.
Set Boundary Values to Hybrid so that Temperature is taken at the wall.
Next, create a User Surface (Insert->Location->User Surface) using the Method Offset from Surface. Select the surface to offset from and the desired offset distance that's outside the thermal boundary layer.
Use the ruler in the viewer to get a sense of scale to select the distance.
In order to offset the new surface into the fluid you may need to use a negative distance you'll need to inspect the offset surface to make sure it's being offset in the correct direction.
Under File->Export, export Temperature using the User Surface just created.
Open the first .csv file, save it as an xls file. Open the second .csv and either copy the Offset Surface Temperature to the .xls file or import the sheet.
The location of the Offset Surface Temperature corresponds to the Wall Temperature value offset normal to the wall by the specified offset distance.
In MS Excel, calculate a new heat transfer coefficient using heat flux, wall temperature and the new fluid temperature based on the offset surface.