Update: December 17, 2018

$FOAM_TUTORIALS/compressible/rhoCentralFoam/biconic25-55Run35

We calculate the supersonic air flow hitting the wall at an angle for 0.001 seconds.

The air flows in from the region "freestream" at 2713 m/s and out from the region "outlet". The region "cone" is a wall. Only side A in the figure below has no thickness, and the entire analysis region is wedge-shaped.

Model geometry

For the wall of the region "cone", we use a Maxwell slip model that can represent multiple slip states depending on the temperature and curvature of the surface.

The turbulence model is not used, and the calculation is performed as a pseudo 2-dimensional mesh with one mesh in the circumferential direction of the wedge. And a converged solution is used as the initial condition.

The meshes are as follows, and the number of mesh is 32385.

Meshes

Mesh near the junction of region "outlet" and region "cone"

The calculation result is as follows.

Flow velocity at final time (U)

Pressure at final time (p)

We can see that the slip state changes discontinuously on a region "cone".

cp -r $FOAM_TUTORIALS/compressible/rhoCentralFoam/biconic25-55Run35 biconic25-55Run35

cd biconic25-55Run35

blockMesh

datToFoam grid256.dat

# Degenerate short edges and join them with edges in a line

CONST="constant"

cat $CONST/pointsHeader $CONST/points.tmp > $CONST/polyMesh/points

collapseEdges -overwrite

# Changed the patch type for boundary conditions to wedge

mv $CONST/polyMesh/boundary $CONST/polyMesh/boundary.bak

sed -f $CONST/wedgeScr $CONST/polyMesh/boundary.bak > $CONST/polyMesh/boundary

rm $CONST/polyMesh/boundary.bak

rhoCentralFoam

paraFoam

cd biconic25-55Run35

blockMesh

datToFoam grid256.dat

# Degenerate short edges and join them with edges in a line

CONST="constant"

cat $CONST/pointsHeader $CONST/points.tmp > $CONST/polyMesh/points

collapseEdges -overwrite

# Changed the patch type for boundary conditions to wedge

mv $CONST/polyMesh/boundary $CONST/polyMesh/boundary.bak

sed -f $CONST/wedgeScr $CONST/polyMesh/boundary.bak > $CONST/polyMesh/boundary

rm $CONST/polyMesh/boundary.bak

rhoCentralFoam

paraFoam

25分09.86 seconds *Single, Inter(R) Core(TM) i7-8700 CPU @ 3.20GHz 3.19GHz

- OpenFOAM-4.x/applications/solvers/compressible/rhoCentralFoam/BCs/U/maxwellSlipUFvPatchVectorField.H - GitHub
- "The Generalized Maxwell-Slip Model: A Novel Model for Friction Simulation and Compensation", Farid Al-Bender, Vincent Lampaert, and Jan Swevers, IEEE TRANSACTIONS ON AUTOMATIC CONTROL, VOL. 50, NO. 11, NOVEMBER 2005.（PDF）