Henry Weller authored Oct 30, 2017 and Andrew Heather committed May 16, 2018

ENH: compressibleInterPhaseTransportFoam: New variant of compressibleInterFoam supporting separate phase stress models

In this version of compressibleInterFoam separate stress models (laminar,
non-Newtonian, LES or RAS) are instantiated for each of the two phases allowing
for completely different modeling for the phases.

e.g. in the climbingRod tutorial case provided a Newtonian laminar model is
instantiated for the air and a Maxwell non-Newtonian model is instantiated for
the viscoelastic liquid.  To stabilize the Maxwell model in regions where the
liquid phase-fraction is 0 the new symmTensorPhaseLimitStabilization fvOption is
applied.

Other phase stress modeling combinations are also possible, e.g. the air may be
turbulent but the liquid laminar and an RAS or LES model applied to the air
only.  However, to stabilize this combination a suitable fvOption would need to
be applied to the turbulence properties where the air phase-fraction is 0.

Henry G. Weller, Chris Greenshields
CFD Direct Ltd.