For turbulent flow in the energy equation has to be replaced by
where
![]() |
(703) |
where
is the turbulent Prandl number. Therefore, one now
arrives at:
![]() |
(704) |
where
and
![]() |
(705) |
is the turbulence frequency. The dynamic turbulent viscosity
can be written as
.
The boundary conditions for the diffusion term amount to:
![]() |
(706) |
![]() |
(707) |
Either the temperature is given or the heat flux is given (may be zero as for adiabatic conditions). If the temperature is given the treatment is analogous to the case of an inlet, if the heat flux is given the solution is trivial since the diffusion term for an external surface is nothing else than the value of the heat flux through this surface.