Files
openfoam/src/fieldSources/derived/rotorDiskSource/rotorDiskSource.C
2012-10-19 10:56:36 +01:00

695 lines
19 KiB
C

/*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration |
\\ / A nd | Copyright (C) 2011-2012 OpenFOAM Foundation
\\/ M anipulation |
-------------------------------------------------------------------------------
License
This file is part of OpenFOAM.
OpenFOAM is free software: you can redistribute it and/or modify it
under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
for more details.
You should have received a copy of the GNU General Public License
along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>.
\*---------------------------------------------------------------------------*/
#include "rotorDiskSource.H"
#include "addToRunTimeSelectionTable.H"
#include "mathematicalConstants.H"
#include "trimModel.H"
#include "unitConversion.H"
#include "fvMatrices.H"
#include "syncTools.H"
using namespace Foam::constant;
// * * * * * * * * * * * * * Static Member Functions * * * * * * * * * * * * //
namespace Foam
{
defineTypeNameAndDebug(rotorDiskSource, 0);
addToRunTimeSelectionTable(basicSource, rotorDiskSource, dictionary);
template<> const char* NamedEnum<rotorDiskSource::geometryModeType, 2>::
names[] =
{
"auto",
"specified"
};
const NamedEnum<rotorDiskSource::geometryModeType, 2>
rotorDiskSource::geometryModeTypeNames_;
template<> const char* NamedEnum<rotorDiskSource::inletFlowType, 3>::
names[] =
{
"fixed",
"surfaceNormal",
"local"
};
const NamedEnum<rotorDiskSource::inletFlowType, 3>
rotorDiskSource::inletFlowTypeNames_;
}
// * * * * * * * * * * * * Protected Member Functions * * * * * * * * * * * //
void Foam::rotorDiskSource::checkData()
{
// set inflow type
switch (selectionMode())
{
case smCellSet:
case smCellZone:
case smAll:
{
// set the profile ID for each blade section
profiles_.connectBlades(blade_.profileName(), blade_.profileID());
switch (inletFlow_)
{
case ifFixed:
{
coeffs_.lookup("inletVelocity") >> inletVelocity_;
break;
}
case ifSurfaceNormal:
{
scalar UIn
(
readScalar(coeffs_.lookup("inletNormalVelocity"))
);
inletVelocity_ = -coordSys_.e3()*UIn;
break;
}
case ifLocal:
{
// do nothing
break;
}
default:
{
FatalErrorIn("void rotorDiskSource::checkData()")
<< "Unknown inlet velocity type" << abort(FatalError);
}
}
break;
}
default:
{
FatalErrorIn("void rotorDiskSource::checkData()")
<< "Source cannot be used with '"
<< selectionModeTypeNames_[selectionMode()]
<< "' mode. Please use one of: " << nl
<< selectionModeTypeNames_[smCellSet] << nl
<< selectionModeTypeNames_[smCellZone] << nl
<< selectionModeTypeNames_[smAll]
<< exit(FatalError);
}
}
}
void Foam::rotorDiskSource::setFaceArea(vector& axis, const bool correct)
{
area_ = 0.0;
static const scalar tol = 0.8;
const label nInternalFaces = mesh_.nInternalFaces();
const polyBoundaryMesh& pbm = mesh_.boundaryMesh();
const vectorField& Sf = mesh_.Sf();
const scalarField& magSf = mesh_.magSf();
vector n = vector::zero;
// calculate cell addressing for selected cells
labelList cellAddr(mesh_.nCells(), -1);
UIndirectList<label>(cellAddr, cells_) = identity(cells_.size());
labelList nbrFaceCellAddr(mesh_.nFaces() - nInternalFaces, -1);
forAll(pbm, patchI)
{
const polyPatch& pp = pbm[patchI];
if (pp.coupled())
{
forAll(pp, i)
{
label faceI = pp.start() + i;
label nbrFaceI = faceI - nInternalFaces;
label own = mesh_.faceOwner()[faceI];
nbrFaceCellAddr[nbrFaceI] = cellAddr[own];
}
}
}
// correct for parallel running
syncTools::swapBoundaryFaceList(mesh_, nbrFaceCellAddr);
// add internal field contributions
for (label faceI = 0; faceI < nInternalFaces; faceI++)
{
const label own = cellAddr[mesh_.faceOwner()[faceI]];
const label nbr = cellAddr[mesh_.faceNeighbour()[faceI]];
if ((own != -1) && (nbr == -1))
{
vector nf = Sf[faceI]/magSf[faceI];
if ((nf & axis) > tol)
{
area_[own] += magSf[faceI];
n += Sf[faceI];
}
}
else if ((own == -1) && (nbr != -1))
{
vector nf = Sf[faceI]/magSf[faceI];
if ((-nf & axis) > tol)
{
area_[nbr] += magSf[faceI];
n -= Sf[faceI];
}
}
}
// add boundary contributions
forAll(pbm, patchI)
{
const polyPatch& pp = pbm[patchI];
const vectorField& Sfp = mesh_.Sf().boundaryField()[patchI];
const scalarField& magSfp = mesh_.magSf().boundaryField()[patchI];
if (pp.coupled())
{
forAll(pp, j)
{
const label faceI = pp.start() + j;
const label own = cellAddr[mesh_.faceOwner()[faceI]];
const bool nbr = nbrFaceCellAddr[faceI - nInternalFaces];
const vector nf = Sfp[j]/magSfp[j];
if ((own != -1) && (nbr == -1) && ((nf & axis) > tol))
{
area_[own] += magSfp[j];
n += Sfp[j];
}
}
}
else
{
forAll(pp, j)
{
const label faceI = pp.start() + j;
const label own = cellAddr[mesh_.faceOwner()[faceI]];
const vector nf = Sfp[j]/magSfp[j];
if ((own != -1) && ((nf & axis) > tol))
{
area_[own] += magSfp[j];
n += Sfp[j];
}
}
}
}
if (correct)
{
reduce(n, sumOp<vector>());
axis = n/mag(n);
}
}
void Foam::rotorDiskSource::createCoordinateSystem()
{
// construct the local rotor co-prdinate system
vector origin(vector::zero);
vector axis(vector::zero);
vector refDir(vector::zero);
geometryModeType gm =
geometryModeTypeNames_.read(coeffs_.lookup("geometryMode"));
switch (gm)
{
case gmAuto:
{
// determine rotation origin (cell volume weighted)
scalar sumV = 0.0;
const scalarField& V = mesh_.V();
const vectorField& C = mesh_.C();
forAll(cells_, i)
{
const label cellI = cells_[i];
sumV += V[cellI];
origin += V[cellI]*C[cellI];
}
reduce(origin, sumOp<vector>());
reduce(sumV, sumOp<scalar>());
origin /= sumV;
// determine first radial vector
vector dx1(vector::zero);
scalar magR = -GREAT;
forAll(cells_, i)
{
const label cellI = cells_[i];
vector test = C[cellI] - origin;
if (mag(test) > magR)
{
dx1 = test;
magR = mag(test);
}
}
reduce(dx1, maxMagSqrOp<vector>());
magR = mag(dx1);
// determine second radial vector and cross to determine axis
forAll(cells_, i)
{
const label cellI = cells_[i];
vector dx2 = C[cellI] - origin;
if (mag(dx2) > 0.5*magR)
{
axis = dx1 ^ dx2;
if (mag(axis) > SMALL)
{
break;
}
}
}
reduce(axis, maxMagSqrOp<vector>());
axis /= mag(axis);
// correct the axis direction using a point above the rotor
{
vector pointAbove(coeffs_.lookup("pointAbove"));
vector dir = pointAbove - origin;
dir /= mag(dir);
if ((dir & axis) < 0)
{
axis *= -1.0;
}
}
coeffs_.lookup("refDirection") >> refDir;
// set the face areas and apply correction to calculated axis
// e.g. if cellZone is more than a single layer in thickness
setFaceArea(axis, true);
break;
}
case gmSpecified:
{
coeffs_.lookup("origin") >> origin;
coeffs_.lookup("axis") >> axis;
coeffs_.lookup("refDirection") >> refDir;
setFaceArea(axis, false);
break;
}
default:
{
FatalErrorIn("rotorDiskSource::createCoordinateSystem()")
<< "Unknown geometryMode " << geometryModeTypeNames_[gm]
<< ". Available geometry modes include "
<< geometryModeTypeNames_ << exit(FatalError);
}
}
coordSys_ = cylindricalCS("rotorCoordSys", origin, axis, refDir, false);
const scalar sumArea = gSum(area_);
const scalar diameter = Foam::sqrt(4.0*sumArea/mathematical::pi);
Info<< " Rotor gometry:" << nl
<< " - disk diameter = " << diameter << nl
<< " - disk area = " << sumArea << nl
<< " - origin = " << coordSys_.origin() << nl
<< " - r-axis = " << coordSys_.e1() << nl
<< " - psi-axis = " << coordSys_.e2() << nl
<< " - z-axis = " << coordSys_.e3() << endl;
}
void Foam::rotorDiskSource::constructGeometry()
{
const vectorField& C = mesh_.C();
forAll(cells_, i)
{
if (area_[i] > ROOTVSMALL)
{
const label cellI = cells_[i];
// position in (planar) rotor co-ordinate system
x_[i] = coordSys_.localPosition(C[cellI]);
// cache max radius
rMax_ = max(rMax_, x_[i].x());
// swept angle relative to rDir axis [radians] in range 0 -> 2*pi
scalar psi = x_[i].y();
// blade flap angle [radians]
scalar beta =
flap_.beta0 - flap_.beta1c*cos(psi) - flap_.beta2s*sin(psi);
// determine rotation tensor to convert from planar system into the
// rotor cone system
scalar c = cos(beta);
scalar s = sin(beta);
R_[i] = tensor(c, 0, -s, 0, 1, 0, s, 0, c);
invR_[i] = R_[i].T();
}
}
}
Foam::tmp<Foam::vectorField> Foam::rotorDiskSource::inflowVelocity
(
const volVectorField& U
) const
{
switch (inletFlow_)
{
case ifFixed:
case ifSurfaceNormal:
{
return tmp<vectorField>
(
new vectorField(mesh_.nCells(), inletVelocity_)
);
break;
}
case ifLocal:
{
return U.internalField();
break;
}
default:
{
FatalErrorIn
(
"Foam::tmp<Foam::vectorField> "
"Foam::rotorDiskSource::inflowVelocity"
"(const volVectorField&) const"
) << "Unknown inlet flow specification" << abort(FatalError);
}
}
return tmp<vectorField>(new vectorField(mesh_.nCells(), vector::zero));
}
// * * * * * * * * * * * * * * * Constructors * * * * * * * * * * * * * * * //
Foam::rotorDiskSource::rotorDiskSource
(
const word& name,
const word& modelType,
const dictionary& dict,
const fvMesh& mesh
)
:
basicSource(name, modelType, dict, mesh),
rhoName_("none"),
rhoRef_(1.0),
omega_(0.0),
nBlades_(0),
inletFlow_(ifLocal),
inletVelocity_(vector::zero),
tipEffect_(1.0),
flap_(),
x_(cells_.size(), vector::zero),
R_(cells_.size(), I),
invR_(cells_.size(), I),
area_(cells_.size(), 0.0),
coordSys_(false),
rMax_(0.0),
trim_(trimModel::New(*this, coeffs_)),
blade_(coeffs_.subDict("blade")),
profiles_(coeffs_.subDict("profiles"))
{
read(dict);
}
// * * * * * * * * * * * * * * * * Destructor * * * * * * * * * * * * * * * //
Foam::rotorDiskSource::~rotorDiskSource()
{}
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
void Foam::rotorDiskSource::calculate
(
const vectorField& U,
const scalarField& thetag,
vectorField& force,
const bool divideVolume,
const bool output
) const
{
const scalarField& V = mesh_.V();
const bool compressible = this->compressible();
tmp<volScalarField> trho(rho());
// logging info
scalar dragEff = 0.0;
scalar liftEff = 0.0;
scalar AOAmin = GREAT;
scalar AOAmax = -GREAT;
forAll(cells_, i)
{
if (area_[i] > ROOTVSMALL)
{
const label cellI = cells_[i];
const scalar radius = x_[i].x();
// velocity in local cylindrical reference frame
vector Uc = coordSys_.localVector(U[cellI]);
// transform from rotor cylindrical into local coning system
Uc = R_[i] & Uc;
// set radial component of velocity to zero
Uc.x() = 0.0;
// set blade normal component of velocity
Uc.y() = radius*omega_ - Uc.y();
// determine blade data for this radius
// i2 = index of upper radius bound data point in blade list
scalar twist = 0.0;
scalar chord = 0.0;
label i1 = -1;
label i2 = -1;
scalar invDr = 0.0;
blade_.interpolate(radius, twist, chord, i1, i2, invDr);
// flip geometric angle if blade is spinning in reverse (clockwise)
scalar alphaGeom = thetag[i] + twist;
if (omega_ < 0)
{
alphaGeom = mathematical::pi - alphaGeom;
}
// effective angle of attack
scalar alphaEff = alphaGeom - atan2(-Uc.z(), Uc.y());
AOAmin = min(AOAmin, alphaEff);
AOAmax = max(AOAmax, alphaEff);
// determine profile data for this radius and angle of attack
const label profile1 = blade_.profileID()[i1];
const label profile2 = blade_.profileID()[i2];
scalar Cd1 = 0.0;
scalar Cl1 = 0.0;
profiles_[profile1].Cdl(alphaEff, Cd1, Cl1);
scalar Cd2 = 0.0;
scalar Cl2 = 0.0;
profiles_[profile2].Cdl(alphaEff, Cd2, Cl2);
scalar Cd = invDr*(Cd2 - Cd1) + Cd1;
scalar Cl = invDr*(Cl2 - Cl1) + Cl1;
// apply tip effect for blade lift
scalar tipFactor = neg(radius/rMax_ - tipEffect_);
// calculate forces perpendicular to blade
scalar pDyn = 0.5*magSqr(Uc);
if (compressible)
{
pDyn *= trho()[cellI];
}
scalar f = pDyn*chord*nBlades_*area_[i]/radius/mathematical::twoPi;
vector localForce = vector(0.0, -f*Cd, tipFactor*f*Cl);
// accumulate forces
dragEff += rhoRef_*localForce.y();
liftEff += rhoRef_*localForce.z();
// convert force from local coning system into rotor cylindrical
localForce = invR_[i] & localForce;
// convert force to global cartesian co-ordinate system
force[cellI] = coordSys_.globalVector(localForce);
if (divideVolume)
{
force[cellI] /= V[cellI];
}
}
}
if (output)
{
reduce(AOAmin, minOp<scalar>());
reduce(AOAmax, maxOp<scalar>());
reduce(dragEff, sumOp<scalar>());
reduce(liftEff, sumOp<scalar>());
Info<< type() << " output:" << nl
<< " min/max(AOA) = " << radToDeg(AOAmin) << ", "
<< radToDeg(AOAmax) << nl
<< " Effective drag = " << dragEff << nl
<< " Effective lift = " << liftEff << endl;
}
}
void Foam::rotorDiskSource::addSup(fvMatrix<vector>& eqn, const label fieldI)
{
dimensionSet dims = dimless;
if (eqn.dimensions() == dimForce)
{
coeffs_.lookup("rhoName") >> rhoName_;
dims.reset(dimForce/dimVolume);
}
else
{
coeffs_.lookup("rhoRef") >> rhoRef_;
dims.reset(dimForce/dimVolume/dimDensity);
}
volVectorField force
(
IOobject
(
"rotorForce",
mesh_.time().timeName(),
mesh_,
IOobject::NO_READ,
IOobject::NO_WRITE
),
mesh_,
dimensionedVector("zero", dims, vector::zero)
);
const volVectorField& U = eqn.psi();
const vectorField Uin(inflowVelocity(U));
trim_->correct(Uin, force);
calculate(Uin, trim_->thetag(), force);
// add source to rhs of eqn
eqn -= force;
if (mesh_.time().outputTime())
{
force.write();
}
}
void Foam::rotorDiskSource::writeData(Ostream& os) const
{
os << indent << name_ << endl;
dict_.write(os);
}
bool Foam::rotorDiskSource::read(const dictionary& dict)
{
if (basicSource::read(dict))
{
coeffs_.lookup("fieldNames") >> fieldNames_;
applied_.setSize(fieldNames_.size(), false);
// read co-ordinate system/geometry invariant properties
scalar rpm(readScalar(coeffs_.lookup("rpm")));
omega_ = rpm/60.0*mathematical::twoPi;
coeffs_.lookup("nBlades") >> nBlades_;
inletFlow_ = inletFlowTypeNames_.read(coeffs_.lookup("inletFlowType"));
coeffs_.lookup("tipEffect") >> tipEffect_;
const dictionary& flapCoeffs(coeffs_.subDict("flapCoeffs"));
flapCoeffs.lookup("beta0") >> flap_.beta0;
flapCoeffs.lookup("beta1c") >> flap_.beta1c;
flapCoeffs.lookup("beta2s") >> flap_.beta2s;
flap_.beta0 = degToRad(flap_.beta0);
flap_.beta1c = degToRad(flap_.beta1c);
flap_.beta2s = degToRad(flap_.beta2s);
// create co-ordinate system
createCoordinateSystem();
// read co-odinate system dependent properties
checkData();
constructGeometry();
trim_->read(coeffs_);
if (debug)
{
writeField("thetag", trim_->thetag()(), true);
writeField("faceArea", area_, true);
}
return true;
}
else
{
return false;
}
}
// ************************************************************************* //