Viscous Dissipation
This subnode should be used to account for the heat source coming from the transformation of kinetic energy into internal energy due to viscous stresses. Such effect is expected in fluid regions with large velocity gradients or with high turbulence levels.
Viscous Dissipation
The Qvd input should be specified either as a User defined value, or as the viscous dissipation term contribution straight from the fluid flow interfaces.
For laminar flows, it is defined by
where τ is the viscous tensor.
When the Nonisothermal Flow multiphysics coupling node is added, the effect of viscous dissipation can be taken into account by selecting the Include viscous dissipation check box under the Flow Heating section. In this case, the Viscous Dissipation feature is overriden by the multiphysics coupling node’s contribution.
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Fluid
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Porous Medium
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Phase Change Material
This feature was previously called Viscous Heating.
Location in User Interface
Context menus
 Heat Transfer in Fluids>Fluid>Viscous Dissipation
Heat Transfer in Fluids>Phase Change Material>Viscous Dissipation
Heat Transfer in Fluids>Porous Medium>Viscous Dissipation
More locations are available. For example:
Heat Transfer in Solids>Fluid>Viscous Dissipation
Heat Transfer in Solids>Phase Change Material>Viscous Dissipation
Heat Transfer in Solids>Porous Medium>Viscous Dissipation
Heat Transfer in Moist Air>Moist Air>Viscous Dissipation
Ribbon
Physics Tab with Fluid, Phase Change Material, Moist Air, or Porous Medium selected in the model tree:
Attributes>Viscous Dissipation