In CFD-Post, the heat flux is provided at walls & interfaces only. As a workaround, it can be re-computed. 1. Re-compute the temperature gradient in CFD Post: New Variable –> Method: Gradient –> Gradient of: Temperature. It will be named Temperature.Gradient (in the category User Defined) 2. Create three expressions for the individual components myqx = Temperature.Gradient X * Thermal Conductivity myqy = Temperature.Gradient Y * Thermal Conductivity myqz = Temperature.Gradient Z * Thermal Conductivity 3. Create ‘myheatflux’ New Variable –> method: Expressions –> Vector –> use the expressions defined before