Convective Heat Losses
The Convective Heat Losses node is available when the Compute particle temperature check box is selected in the physics interface Additional Variables section. Use the Convective Heat Losses node to model the heating or cooling of a particle due to convective heat exchange with the surrounding fluid.
The temperature within the particle is assumed to be uniform; that is, heat transfer by conduction within the particle takes place on a much shorter time scale than heat transfer by convection at the surface. This is equivalent to the assumption that the particle Biot number is much smaller than unity, and allows each particle’s temperature to be stored as a single number instead of a temperature distribution.
Model Input
The model input for the Temperature T (SI unit: K) is always shown in the settings window for this feature, even if there are no material properties that depend on it.
Convective Heat Losses
Choose an option from the Heat source definition list: Specify heat transfer coefficient or Specify Nusselt number (the default).
If Specify heat transfer coefficient is selected, enter a value or expression for the Heat transfer coefficient h (SI unit: W/(m2 K)). The default is 10 W/(m2 K).
If Specify Nusselt number is selected, then by default the Thermal conductivity k (SI unit: W/(m K)) is taken From material. Select User defined from the list to enter a value or expression. For this purpose the conductivity is always assumed isotropic. Also enter a value or expression for the dimensionless Nusselt number Nu. The default value, 2, is the theoretical limit for a sphere in a fluid with zero relative velocity.
Computing Particle Temperature in the theory section.