From 12ba22bebfa430f0a352f75474aa28c6c2a381ba Mon Sep 17 00:00:00 2001
From: Andrew Heather <>
Date: Wed, 10 Aug 2022 10:29:13 +0100
Subject: [PATCH] ENH: DESModel - stabilisation of Ssigma function
- Code supplied by Marian Fuchs, Upstream CFD GmbH
---
.../turbulenceModels/DES/DESModel/DESModel.C | 54 +++++++++----------
1 file changed, 26 insertions(+), 28 deletions(-)
diff --git a/src/TurbulenceModels/turbulenceModels/DES/DESModel/DESModel.C b/src/TurbulenceModels/turbulenceModels/DES/DESModel/DESModel.C
index b74b937ab00..f330aecfcfa 100644
--- a/src/TurbulenceModels/turbulenceModels/DES/DESModel/DESModel.C
+++ b/src/TurbulenceModels/turbulenceModels/DES/DESModel/DESModel.C
@@ -91,36 +91,35 @@ tmp<volScalarField> DESModel<BasicTurbulenceModel>::Ssigma
const dimensionedScalar& coeff
)
{
- const volTensorField G(gradU.T() & gradU);
+ // Limiter
+ const dimensionedScalar eps0("eps0", dimless, SMALL);
+ const dimensionedScalar eps2("eps2", dimless/sqr(dimTime), SMALL);
+ const dimensionedScalar eps4("eps4", dimless/pow4(dimTime), SMALL);
+ const dimensionedScalar max2("max2", dimless/sqr(dimTime), GREAT);
+ const dimensionedTensor maxTen2
+ (
+ "maxTen2",
+ dimless/sqr(dimTime),
+ tensor::max
+ );
+ const dimensionedTensor minTen2
+ (
+ "minTen2",
+ dimless/sqr(dimTime),
+ tensor::min
+ );
+
+ const volTensorField G(max(min(gradU.T() & gradU, maxTen2), minTen2));
// Tensor invariants
const volScalarField I1(tr(G));
- const volScalarField I2(0.5*(sqr(tr(G)) - tr(G & G)));
+ const volScalarField I2(0.5*(sqr(I1) - tr(G & G)));
const volScalarField I3(det(G));
- const volScalarField alpha1
- (
- max
- (
- sqr(I1)/9.0 - I2/3.0,
- dimensionedScalar("SMALL", dimless/pow4(dimTime), SMALL)
- )
- );
+ const volScalarField alpha1(max(sqr(I1)/9.0 - I2/3.0, eps4));
- const volScalarField alpha2
- (
- pow3
- (
- min
- (
- I1,
- dimensionedScalar("GREAT", dimless/sqr(dimTime), GREAT)
- )
- )/27.0
- - I1*I2/6.0 + I3/2.0
- );
+ const volScalarField alpha2(pow3(min(I1, max2))/27.0 - I1*I2/6.0 + I3/2.0);
- const dimensionedScalar eps0("SMALL", dimless, SMALL);
const volScalarField alpha3
(
1.0/3.0
@@ -134,19 +133,18 @@ tmp<volScalarField> DESModel<BasicTurbulenceModel>::Ssigma
)
);
- const dimensionedScalar sig0("SMALL", dimless/sqr(dimTime), SMALL);
const scalar piBy3 = constant::mathematical::pi/3.0;
const volScalarField sigma1
(
- sqrt(max(I1/3.0 + 2.0*sqrt(alpha1)*cos(alpha3), sig0))
+ sqrt(max(I1/3.0 + 2.0*sqrt(alpha1)*cos(alpha3), eps2))
);
const volScalarField sigma2
(
- sqrt(max(I1/3.0 - 2.0*sqrt(alpha1)*cos(piBy3 + alpha3), sig0))
+ sqrt(max(I1/3.0 - 2.0*sqrt(alpha1)*cos(piBy3 + alpha3), eps2))
);
const volScalarField sigma3
(
- sqrt(max(I1/3.0 - 2.0*sqrt(alpha1)*cos(piBy3 - alpha3), sig0))
+ sqrt(max(I1/3.0 - 2.0*sqrt(alpha1)*cos(piBy3 - alpha3), eps2))
);
return
@@ -154,7 +152,7 @@ tmp<volScalarField> DESModel<BasicTurbulenceModel>::Ssigma
*sigma3
*(sigma1 - sigma2)
*(sigma2 - sigma3)
- /max(sqr(sigma1), sig0);
+ /max(sqr(sigma1), eps2);
}
--
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