Alsvinn  0.5.3
The fast FVM simulator with UQ support
Rusanov.hpp
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1 /* Copyright (c) 2018 ETH Zurich, Kjetil Olsen Lye
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15 
16 #pragma once
17 #include "alsfvm/types.hpp"
18 
19 #include <algorithm>
20 #include <cmath>
21 
22 namespace alsfvm {
23 namespace numflux {
24 
31 template<class Equation>
32 class Rusanov {
33 public:
37  static const std::string name;
38 
39  template<int direction>
40  __device__ __host__ inline static real computeFlux(const Equation& eq,
41  const typename Equation::AllVariables& left,
42  const typename Equation::AllVariables& right,
43  typename Equation::ConservedVariables& F) {
44  typename Equation::ConservedVariables fluxLeft;
45  eq.template computePointFlux<direction>(left, fluxLeft);
46  typename Equation::ConservedVariables fluxRight;
47  eq.template computePointFlux<direction>(right, fluxRight);
48  real eigenLeft = fabs(eq.template computeEigenValues<direction>(left));
49  real eigenRight = fabs(eq.template computeEigenValues<direction>(right));
50 
51  real eigenMax = fmax(eigenLeft, eigenRight);
52  F = 0.5 * (fluxLeft + fluxRight) - 0.5 * eigenMax * (right.u - left.u);
53 
54  // This looks a bit weird, but it is OK. The basic principle is that AllVariables
55  // is both a conservedVariable and an extra variable, hence we need to pass
56  // it twice since this function expects both.
57  return fmax(eq.template computeWaveSpeed<direction>(left, left),
58  eq.template computeWaveSpeed<direction>(right, right));
59  }
60 };
61 } // namespace alsfvm
62 } // namespace numflux
#define __host__
Definition: types.hpp:46
Definition: Rusanov.hpp:32
double real
Definition: types.hpp:65
static const std::string name
name is "rusanov"
Definition: Rusanov.hpp:37
#define __device__
Definition: types.hpp:45
__device__ static __host__ real computeFlux(const Equation &eq, const typename Equation::AllVariables &left, const typename Equation::AllVariables &right, typename Equation::ConservedVariables &F)
Definition: Rusanov.hpp:40
Various utility functions to implement the tecno flux.
Definition: types.hpp:30