IBM: Immersed boundary method specific post-processing

Specific post-processing for immersed boundaries (IB).

These functions work with a solution tree “t”, a geometry tree “tb”, and/or a connectivity tree “tc”.

List of functions

– Post-processing of IBs

`Post.IBM.extractIBMWallFields`(tc[, tb, …])	Extract the value of the flow field at the IBM target points onto the surface.
`Post.IBM.extractIBMInfo`(tc_in[, filename_out])	Extracts the geometrical information required for the IBM (i e wall points, target points, and image points).
`Post.IBM.extractShearStress`(ts)	Compute the shear stress on the IB surface.
`Post.IBM.computeExtraVariables`(ts, PInf, QInf)	Computes additional variables required for IBM post-processing..
`Post.IBM.extractPressureHO`(tc)	1st order extrapolation of the pressure at the immersed boundary (IB).
`Post.IBM.extractPressureHO2`(tc)	2nd order extrapolation of the pressure at the immersed boundary (IB).
`Post.IBM.extractConvectiveTerms`(tc)	Computes the convective terms required for the thin boundary layers equations (TBLE) and stores them in the tc.

# - extractConvectiveTerms (pyTree) -
import Converter.Internal as Internal
import Converter.PyTree as C
import Generator.PyTree as G
import Geom.PyTree as D
import KCore.test as test
import Post.IBM as P_IBM
import copy
import numpy

a = G.cart((0.,0.,0.), (0.1,0.1,0.2), (10,11,12))
a = C.node2Center(a)
for z in Internal.getZones(a):
    Internal._createChild(z, 'IBCD_2_'+z[0] , 'ZoneSubRegion_t', value=z[0])

Nlength  = numpy.zeros((10),numpy.float64)
for z in Internal.getZones(a):
    subRegions = Internal.getNodesFromType1(z, 'ZoneSubRegion_t')
    for zsr in subRegions:
        Internal._createChild(zsr, 'ZoneRole', 'DataArray_t', value='Donor')
        Internal._createChild(zsr, 'GridLocation', 'GridLocation_t', value='CellCenter')
        
        zsr[2].append(['CoordinateX_PW', copy.copy(Nlength)+13, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PW', copy.copy(Nlength)+13, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PW', copy.copy(Nlength)+13, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        
a=P_IBM.extractIBMInfo(a)
C.convertPyTree2File(a,'out.cgns')

Post.IBM.extractIBMWallFields(tc, tb=None, coordRef='wall', famZones=[], front=1)

Project the solution at IBM wall points onto the vertices of the surface. If tb is None, returns the cloud of points, else interpolate by Moving Least Squares interpolation on tb. Returns density, pressure, utau, yplus, velocity components.

Parameters

tc ([zone, list of zones, base, tree]) – connectivity tree
tb ([zone, list of zones, base, tree]) – surface mesh (TRI-type)
coordRef (string) – coordinates of IBM points to be projected (default is IBM wall points) :’wall’,’cible’,’image’
famZones (list of names of families) – list of families of IBCs to be projected

Returns

surface tree with solution (density, pressure, friction velocity, yplus)

Example of use:

Project the solution at IBM wall points onto the vertices of the surface (pyTree):

Post.IBM.extractShearStress(tb)

Computes the shear stress using utau values at vertices of the surface mesh

Parameters: tb ([zone, list of zones, base, tree]) – surface mesh (TRI-type) with density, velocity, utau variable
Returns: surface tree with shear stress variables “ShearStressXX”, “ShearStressYY”,”ShearStressZZ”,”ShearStressXY”, “ShearStressXZ”, “ShearStressYZ”

Example of use:

Computes the shear stress using utau values at vertices of the surface mesh (pyTree):

Post.IBM.computeExtraVariables(tb, PInf, QInf, variables=['Cp','Cf','frictionX','frictionY','frictionZ', 'frictionMagnitude','ShearStress'])

Computes variables using variables density, pressure, utau, and velocity at vertices of tb. Solution is located at cell centers.

Parameters

tb ([zone, list of zones, base, tree]) – surface mesh (TRI-type) with density, velocity, utau variable
PInf (real) – reference pressure to compute Cp
QInf (real) – reference dynamic pressure
variables (list of strings) – list of variables to be computed.

Returns

surface tree with additional variables.

Example of use:

Computes variables using variables density, pressure, utau, and velocity at vertices of tb (pyTree):

#compute shear stress for IBM
import Post.IBM as P_IBM
import Converter.PyTree as C
import Converter.Internal as Internal
import Geom.PyTree as D
import Generator.PyTree as G

a=D.sphere((0,0,0),0.5,N=30)
a = C.convertArray2Tetra(a); a = G.close(a)
C._initVars(a,'{centers:utau}={centers:CoordinateX}**2')
C._initVars(a,'{centers:VelocityX}={centers:CoordinateZ}*{centers:CoordinateY}')
C._initVars(a,'{centers:VelocityY}={centers:CoordinateX}*{centers:CoordinateZ}')
C._initVars(a,'{centers:VelocityZ}={centers:CoordinateX}*{centers:CoordinateY}')
C._initVars(a,'{centers:Density}=1')
C._initVars(a,'{centers:Pressure}=0.71')

P_IBM._computeExtraVariables(a,PInf=0.71, QInf=0.005, variables=['Cp','Cf','ShearStress'])
C.convertPyTree2File(a,"out.cgns")

Post.IBM.extractConvectiveTerms(tc)

Computes the convective terms required for the thin boundary layers equations (TBLE) and stores them in the tc.

Parameters: tc ([zone, list of zones, base, tree]) – connectivity tree
Returns: same as input

Example of use:

Compute the convective terms (pyTree):

# - extractConvectiveTerms (pyTree) -
import Converter.Internal as Internal
import Converter.PyTree as C
import Generator.PyTree as G
import Geom.PyTree as D
import KCore.test as test
import Post.IBM as P_IBM
import copy
import numpy

a = G.cart((0.,0.,0.), (0.1,0.1,0.2), (10,11,12))
a = C.node2Center(a)
for z in Internal.getZones(a):
    Internal._createChild(z, 'IBCD_2_'+z[0] , 'ZoneSubRegion_t', value=z[0])

Nlength  = numpy.zeros((10),numpy.float64)
for z in Internal.getZones(a):
    subRegions = Internal.getNodesFromType1(z, 'ZoneSubRegion_t')
    for zsr in subRegions:
        Internal._createChild(zsr, 'ZoneRole', 'DataArray_t', value='Donor')
        Internal._createChild(zsr, 'GridLocation', 'GridLocation_t', value='CellCenter')
        
        zsr[2].append(['CoordinateX_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PW', copy.copy(Nlength), [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])

        zsr[2].append(['Pressure', Nlength+3, [], 'DataArray_t'])
        zsr[2].append(['Density' , copy.copy(Nlength)+1, [], 'DataArray_t'])
            
        zsr[2].append(['gradxPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradyPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradzPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])

        zsr[2].append(['gradxVelocityX', copy.copy(Nlength)+3, [], 'DataArray_t'])
        zsr[2].append(['gradyVelocityX', copy.copy(Nlength)+3, [], 'DataArray_t'])
        zsr[2].append(['gradzVelocityX', copy.copy(Nlength)+3, [], 'DataArray_t'])

        zsr[2].append(['gradxVelocityY', copy.copy(Nlength)+4, [], 'DataArray_t'])
        zsr[2].append(['gradyVelocityY', copy.copy(Nlength)+4, [], 'DataArray_t'])
        zsr[2].append(['gradzVelocityY', copy.copy(Nlength)+4, [], 'DataArray_t'])

        zsr[2].append(['gradxVelocityZ', copy.copy(Nlength)+5, [], 'DataArray_t'])
        zsr[2].append(['gradyVelocityZ', copy.copy(Nlength)+5, [], 'DataArray_t'])
        zsr[2].append(['gradzVelocityZ', copy.copy(Nlength)+5, [], 'DataArray_t'])

        zsr[2].append(['VelocityX', copy.copy(Nlength)+6, [], 'DataArray_t'])
        zsr[2].append(['VelocityY', copy.copy(Nlength)+7, [], 'DataArray_t'])
        zsr[2].append(['VelocityZ', copy.copy(Nlength)+8, [], 'DataArray_t'])
        
a=P_IBM.extractConvectiveTerms(a)
C.convertPyTree2File(a,'out.cgns')

Post.IBM.extractPressureHO(tc)

1st order extrapolation of the pressure at the IB.

Parameters: tc ([zone, list of zones, base, tree]) – connectivity tree
Returns: same as input

Example of use:

1st order extrapolation of the pressure at the IB (pyTree):

# - extractPressureHO (pyTree) -
import Converter.Internal as Internal
import Converter.PyTree as C
import Generator.PyTree as G
import Geom.PyTree as D
import KCore.test as test
import Post.IBM as P_IBM
import copy
import numpy

a = G.cart((0.,0.,0.), (0.1,0.1,0.2), (10,11,12))
a = C.node2Center(a)
for z in Internal.getZones(a):
    Internal._createChild(z, 'IBCD_2_'+z[0] , 'ZoneSubRegion_t', value=z[0])

Nlength  = numpy.zeros((10),numpy.float64)
for z in Internal.getZones(a):
    subRegions = Internal.getNodesFromType1(z, 'ZoneSubRegion_t')
    for zsr in subRegions:
        Internal._createChild(zsr, 'ZoneRole', 'DataArray_t', value='Donor')
        Internal._createChild(zsr, 'GridLocation', 'GridLocation_t', value='CellCenter')
        
        zsr[2].append(['Pressure', Nlength+3, [], 'DataArray_t'])
        zsr[2].append(['Density' , copy.copy(Nlength)+1, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PW', copy.copy(Nlength), [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        
        zsr[2].append(['gradxPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradyPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradzPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        
a=P_IBM.extractPressureHO(a)
C.convertPyTree2File(a,'out.cgns')

Post.IBM.extractPressureHO2(tc)

2nd order extrapolation of the pressure at the IB.

Parameters: tc ([zone, list of zones, base, tree]) – connectivity tree
Returns: same as input

Example of use:

2nd order extrapolation of the pressure at the IB (pyTree):

# - extractPressureHO2 (pyTree) -
import Converter.Internal as Internal
import Converter.PyTree as C
import Generator.PyTree as G
import Geom.PyTree as D
import KCore.test as test
import Post.IBM as P_IBM
import copy
import numpy

a = G.cart((0.,0.,0.), (0.1,0.1,0.2), (10,11,12))
a = C.node2Center(a)
for z in Internal.getZones(a):
    Internal._createChild(z, 'IBCD_2_'+z[0] , 'ZoneSubRegion_t', value=z[0])

Nlength  = numpy.zeros((10),numpy.float64)
for z in Internal.getZones(a):
    subRegions = Internal.getNodesFromType1(z, 'ZoneSubRegion_t')
    for zsr in subRegions:
        Internal._createChild(zsr, 'ZoneRole', 'DataArray_t', value='Donor')
        Internal._createChild(zsr, 'GridLocation', 'GridLocation_t', value='CellCenter')
        
        zsr[2].append(['Pressure', Nlength+3, [], 'DataArray_t'])
        zsr[2].append(['Density' , copy.copy(Nlength)+1, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PW', copy.copy(Nlength), [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PW', copy.copy(Nlength), [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PC', copy.copy(Nlength)+14, [], 'DataArray_t'])
        
        zsr[2].append(['CoordinateX_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateY_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        zsr[2].append(['CoordinateZ_PI', copy.copy(Nlength)+15, [], 'DataArray_t'])
        
        zsr[2].append(['gradxPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradyPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])
        zsr[2].append(['gradzPressure', copy.copy(Nlength)+2, [], 'DataArray_t'])

        zsr[2].append(['gradxxPressure', copy.copy(Nlength)+3, [], 'DataArray_t'])
        zsr[2].append(['gradxyPressure', copy.copy(Nlength)+3, [], 'DataArray_t'])
        zsr[2].append(['gradxzPressure', copy.copy(Nlength)+3, [], 'DataArray_t'])

        zsr[2].append(['gradyxPressure', copy.copy(Nlength)+4, [], 'DataArray_t'])
        zsr[2].append(['gradyyPressure', copy.copy(Nlength)+4, [], 'DataArray_t'])
        zsr[2].append(['gradyzPressure', copy.copy(Nlength)+4, [], 'DataArray_t'])

        zsr[2].append(['gradzxPressure', copy.copy(Nlength)+5, [], 'DataArray_t'])
        zsr[2].append(['gradzyPressure', copy.copy(Nlength)+5, [], 'DataArray_t'])
        zsr[2].append(['gradzzPressure', copy.copy(Nlength)+5, [], 'DataArray_t'])
        
a=P_IBM.extractPressureHO2(a)
C.convertPyTree2File(a,'out.cgns')

IBM: Immersed boundary method specific post-processing

List of functions

Contents

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