mirror of
https://github.com/smyalygames/FiniteVolumeGPU.git
synced 2025-05-18 14:34:13 +02:00
80 lines
2.1 KiB
C
80 lines
2.1 KiB
C
/*
|
|
These CUDA functions implement different types of numerical flux
|
|
functions for the shallow water equations
|
|
|
|
Copyright (C) 2016, 2017, 2018 SINTEF Digital
|
|
|
|
This program 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.
|
|
|
|
This program 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 this program. If not, see <http://www.gnu.org/licenses/>.
|
|
*/
|
|
|
|
#pragma once
|
|
#include "limiters.h"
|
|
|
|
|
|
|
|
|
|
|
|
|
|
inline __device__ float pressure(float4 Q, float gamma) {
|
|
const float rho = Q.x;
|
|
const float rho_u = Q.y;
|
|
const float rho_v = Q.z;
|
|
const float E = Q.w;
|
|
|
|
return (gamma-1.0f)*(E-0.5f*(rho_u*rho_u + rho_v*rho_v)/rho);
|
|
}
|
|
|
|
|
|
__device__ float4 F_func(const float4 Q, float P) {
|
|
const float rho = Q.x;
|
|
const float rho_u = Q.y;
|
|
const float rho_v = Q.z;
|
|
const float E = Q.w;
|
|
|
|
const float u = rho_u/rho;
|
|
|
|
float4 F;
|
|
|
|
F.x = rho_u;
|
|
F.y = rho_u*u + P;
|
|
F.z = rho_v*u;
|
|
F.w = u*(E+P);
|
|
|
|
return F;
|
|
}
|
|
|
|
|
|
|
|
|
|
|
|
/**
|
|
* Central upwind flux function
|
|
*/
|
|
__device__ float4 CentralUpwindFlux(const float4 Qm, float4 Qp, const float gamma) {
|
|
|
|
const float Pp = pressure(Qp, gamma);
|
|
const float4 Fp = F_func(Qp, Pp);
|
|
const float up = Qp.y / Qp.x; // rho*u / rho
|
|
const float cp = sqrt(gamma*Pp*Qp.x); // sqrt(gamma*P/rho)
|
|
|
|
const float Pm = pressure(Qm, gamma);
|
|
const float4 Fm = F_func(Qm, Pm);
|
|
const float um = Qm.y / Qm.x; // rho*u / rho
|
|
const float cm = sqrt(gamma*Pm/Qm.x); // sqrt(g*h)
|
|
|
|
const float am = min(min(um-cm, up-cp), 0.0f); // largest negative wave speed
|
|
const float ap = max(max(um+cm, up+cp), 0.0f); // largest positive wave speed
|
|
|
|
return ((ap*Fm - am*Fp) + ap*am*(Qp-Qm))/(ap-am);
|
|
} |