diff --git a/src/cpu/VirtualFluidsCore/LBM/CumulantK17LBMKernel.h b/src/cpu/VirtualFluidsCore/LBM/CumulantK17LBMKernel.h index 0a5d4058190a7c36956a379e71c049d8e293123e..3052f50e3e48925ed21a3c3af68cc2d247c88a02 100644 --- a/src/cpu/VirtualFluidsCore/LBM/CumulantK17LBMKernel.h +++ b/src/cpu/VirtualFluidsCore/LBM/CumulantK17LBMKernel.h @@ -58,6 +58,11 @@ public: double getCalculationTime() override { return .0; } protected: + inline void forwardInverseChimeraWithK(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2, LBMReal Kinverse, LBMReal K); + inline void backwardInverseChimeraWithK(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2, LBMReal Kinverse, LBMReal K); + inline void forwardChimera(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2); + inline void backwardChimera(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2); + virtual void initDataSet(); LBMReal f[D3Q27System::ENDF + 1]; @@ -73,5 +78,70 @@ protected: LBMReal forcingX3; }; +//////////////////////////////////////////////////////////////////////////////// +//! \brief forward chimera transformation \ref forwardInverseChimeraWithK +//! Transformation from distributions to central moments according to Eq. (6)-(14) in +//! <a href="https://doi.org/10.1016/j.jcp.2017.05.040"><b>[ M. Geier et al. (2017), DOI:10.1016/j.jcp.2017.05.040 ]</b></a> +//! Modified for lower round-off errors. +//////////////////////////////////////////////////////////////////////////////// +inline void CumulantK17LBMKernel::forwardInverseChimeraWithK(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2, LBMReal Kinverse, LBMReal K) +{ + using namespace UbMath; + LBMReal m2 = mfa + mfc; + LBMReal m1 = mfc - mfa; + LBMReal m0 = m2 + mfb; + mfa = m0; + m0 *= Kinverse; + m0 += c1; + mfb = (m1 * Kinverse - m0 * vv) * K; + mfc = ((m2 - c2 * m1 * vv) * Kinverse + v2 * m0) * K; +} +//////////////////////////////////////////////////////////////////////////////// +//! \brief backward chimera transformation \ref backwardInverseChimeraWithK +//! Transformation from central moments to distributions according to Eq. (57)-(65) in +//! <a href="https://doi.org/10.1016/j.jcp.2017.05.040"><b>[ M. Geier et al. (2017), DOI:10.1016/j.jcp.2017.05.040 ]</b></a> +//! ] Modified for lower round-off errors. +//////////////////////////////////////////////////////////////////////////////// +inline void CumulantK17LBMKernel::backwardInverseChimeraWithK(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2, LBMReal Kinverse, LBMReal K) +{ + using namespace UbMath; + LBMReal m0 = (((mfc - mfb) * c1o2 + mfb * vv) * Kinverse + (mfa * Kinverse + c1) * (v2 - vv) * c1o2) * K; + LBMReal m1 = (((mfa - mfc) - c2 * mfb * vv) * Kinverse + (mfa * Kinverse + c1) * (-v2)) * K; + mfc = (((mfc + mfb) * c1o2 + mfb * vv) * Kinverse + (mfa * Kinverse + c1) * (v2 + vv) * c1o2) * K; + mfa = m0; + mfb = m1; +} +//////////////////////////////////////////////////////////////////////////////// +//! \brief forward chimera transformation \ref forwardChimera +//! Transformation from distributions to central moments according to Eq. (6)-(14) in +//! <a href="https://doi.org/10.1016/j.jcp.2017.05.040"><b>[ M. Geier et al. (2017), DOI:10.1016/j.jcp.2017.05.040 ]</b></a> +//! for \f$ K_{abc}=0 \f$. This is to avoid unnessary floating point operations. +//! Modified for lower round-off errors. +//////////////////////////////////////////////////////////////////////////////// +inline void CumulantK17LBMKernel::forwardChimera(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2) +{ + using namespace UbMath; + LBMReal m1 = (mfa + mfc) + mfb; + LBMReal m2 = mfc - mfa; + mfc = (mfc + mfa) + (v2 * m1 - c2 * vv * m2); + mfb = m2 - vv * m1; + mfa = m1; +} +//////////////////////////////////////////////////////////////////////////////// +//! \brief backward chimera transformation \ref backwardChimera +//! Transformation from central moments to distributions according to Eq. (57)-(65) in +//! <a href="https://doi.org/10.1016/j.jcp.2017.05.040"><b>[ M. Geier et al. (2017), DOI:10.1016/j.jcp.2017.05.040 ]</b></a> +//! for \f$ K_{abc}=0 \f$. This is to avoid unnessary floating point operations. +//! Modified for lower round-off errors. +//////////////////////////////////////////////////////////////////////////////// +inline void CumulantK17LBMKernel::backwardChimera(LBMReal& mfa, LBMReal& mfb, LBMReal& mfc, LBMReal vv, LBMReal v2) +{ + using namespace UbMath; + LBMReal ma = (mfc + mfa * (v2 - vv)) * c1o2 + mfb * (vv - c1o2); + LBMReal mb = ((mfa - mfc) - mfa * v2) - c2 * mfb * vv; + mfc = (mfc + mfa * (v2 + vv)) * c1o2 + mfb * (vv + c1o2); + mfb = mb; + mfa = ma; +} -#endif // CumulantK17LBMKernel_h__ \ No newline at end of file +#endif // CumulantK17LBMKernel_h__