File size: 6,260 Bytes
5a600cf | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 | /*---------------------------------------------------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Copyright (C) 2024-2026 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 "propellerDisk.H"
#include "fvMatrix.H"
#include "pimpleNoLoopControl.H"
#include "mathematicalConstants.H"
using namespace Foam::constant::mathematical;
// * * * * * * * * * * * * * * * Member Functions * * * * * * * * * * * * * //
template<class AlphaFieldType, class RhoFieldType>
void Foam::fv::propellerDisk::addActuationDiskAxialInertialResistance
(
vectorField& Usource,
const AlphaFieldType& alpha,
const RhoFieldType& rho,
const volInternalVectorField& U
) const
{
const labelList& cells = zone_.zone();
const scalarField& V = mesh().V();
if (!forcePtr_.valid())
{
forcePtr_ = new volInternalVectorField
(
IOobject
(
typedName("force"),
mesh().time().name(),
mesh(),
IOobject::NO_READ,
IOobject::AUTO_WRITE
),
mesh(),
dimensionedVector
(
rho.dimensions()*U.dimensions()/dimensions::time,
Zero
)
);
}
volInternalVectorField& force = forcePtr_();
const vector centre(this->centre());
const vector normal(this->normal());
const scalar delta = diskThickness(centre);
// hub radius
const scalar rHub = 0.5*dHub_;
// propeller radius
const scalar rProp = 0.5*dProp_;
// Disk area
const scalar A = (rProp - rHub)*(rProp - rHub)*pi;
// Get reference to the n value
const scalar& n = this->n();
// Evaluate advance number J,
// the volumetric mean advance speed of the disk
const scalar J = this->J(U, normal);
// Calculate the mean velocity through the disk
const scalar Udisk = n*dProp_*J;
// ... and the volumetric flux through the disk
const scalar phiDisk = Udisk*A;
if (phiDisk > small)
{
// Correction of advance number J based on mometum theory
// using the propeller curve Kt(J) and Kq(J)
vector2D KtandKq(propellerFunction_->value(J));
scalar Kt = KtandKq.x();
scalar Kq = KtandKq.y();
// Evaluate thrust based on Kt
// Thrust units are force/rho = [m^4/s^2]
scalar T = Kt*sqr(n)*pow4(dProp_);
// Correction for speed based on momentum theory
const scalar Ucorr = T/(2*phiDisk);
const scalar Jcorr = (Udisk - Ucorr)/(n*dProp_);
// Update Kt and Kq based on the corrected J value
KtandKq = propellerFunction_->value(Jcorr);
Kt = KtandKq.x();
Kq = KtandKq.y();
T = Kt*sqr(n)*pow4(dProp_);
const scalar Q = Kq*sqr(n)*pow5(dProp_);
// Correct the rotation speed from the current propulsion force
correctn(T);
// Distribute momentum source
const scalar Ax =
(105/8.0)*T/(delta*pi*(rProp - rHub)*(3*rHub + 4*rProp));
const scalar At =
(105/8.0)*Q/(delta*pi*rProp*(rProp - rHub)*(3*rHub + 4*rProp));
force_ = Zero;
moment_ = Zero;
forAll(cells, i)
{
const label celli = cells[i];
const vector r = mesh().cellCentres()[celli] - centre;
const scalar magr = mag(r);
if (magr > rHub)
{
const scalar rPrime = magr/rProp;
const scalar rHubPrime = rHub/rProp;
// Normalised radius
const scalar rStar =
min((rPrime - rHubPrime)/(1 - rHubPrime), 1);
const scalar Faxial = Ax*rStar*sqrt(1 - rStar);
const scalar Ftangential =
At*rStar*sqrt(1 - rStar)
/(rStar*(1 - rHubPrime) + rHubPrime);
// A unit normal vector to the direction of the tangent
const vector radiusOrtho = normalised(r ^ normal);
const vector rotationVector = radiusOrtho*rotationDir_;
force[celli] =
alpha[celli]*rho[celli]
*(Faxial*normal + Ftangential*rotationVector);
const vector Vfi(V[celli]*force[celli]);
// Integrate the net force and moment
// of the fluid on the propeller
force_ += Vfi;
moment_ += r ^ Vfi;
Usource[celli] += Vfi;
}
}
reduce(force_, sumOp());
reduce(moment_, sumOp());
if
(
mesh().lookupObject<pimpleNoLoopControl>("solutionControl")
.finalIter()
)
{
if (logFile_.valid())
{
logFile_->writeTime
(
n,
J,
Jcorr,
Udisk,
Ucorr,
Kt,
Kq,
T,
Q,
force_,
moment_
);
}
}
}
}
// ************************************************************************* //
|