Heat Models
Viscous Work
Viscous work allows you to include the contribution viscous forces to the energy equations. If you set Include Viscous Work to No, the fluid is treated as inviscid with regard to the energy equation.
Viscous work
where,
Work per second
work per second (J/s)
p
pressure (Pa)
Velocity
surface normal
Viscous
viscous contribution to the stress tensor τij such that Stress tensor
τij
stress tensor, force per unit area in the jth direction on a surface element with an outward unit normal in the ith direction
Convection
Convection is a thermal boundary condition in which the heat flux is a function of convective heat transfer. This is also known as Newton Cooling. It is based on the external convection ambient temperature and an exchange coefficient (h) as shown below:
Convection
where,
Heat
Watts (J/s)
h
exchange coefficient (W/m2-K)
Tambient
convection ambient temperature (K)
T
boundary temperature (K)
Radiation
Radiation is a thermal boundary condition in which the heat flux is a function of radiative heat transfer, based on emissivity, and an external radiation ambient temperature.
Radiation
where,
Heat
Watts (J/s)
ε
emissivity
σ
Stefan-Boltzmann constant = 5.670 x10−8 (W/m2K4)
TRadiation Ambient
radiation ambient temperature (K)
T
boundary temperature (K)