The diffusion term amounts to
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(549) |
which amounts to, taking into account Equations (535) and (536):
where
is the total dynamic viscosity. The first term contains the gradient in normal direction. For face e between
elements P and E it is approximated by:
This amounts to the following approximation:
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(552) |
This amounts to a deferred correction for the gradient. Terms 2 and 3 of
Equation (550) are computed from iteration :
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(553) |
The boundary conditions for the diffusion term deserve special attention. The following cases are distinguished: