compressible_ops_kernel.h

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#ifndef __FLUID_COMPRESSIBLE_OPS_KERNEL_H__
#define __FLUID_COMPRESSIBLE_OPS_KERNEL_H__
 
#include <device/device_config.h>
 
template< typename T>
__global__ void compute_max_wave_speed_kernel(T * __restrict__ max_wave_speed,
                                              const T * __restrict__ u,
                                              const T * __restrict__ v,
                                              const T * __restrict__ w,
                                              const T gamma,
                                              const T * __restrict__ p,
                                              const T * __restrict__ rho,
                                              const int n) {
 
  const int idx = blockIdx.x * blockDim.x + threadIdx.x;
  const int str = blockDim.x * gridDim.x;
 
  for (int i = idx; i < n; i += str) {
    T vel_mag = sqrt(u[i]*u[i] + v[i]*v[i] + w[i]*w[i]);
    T sound_speed = sqrt(gamma * p[i] / rho[i]);
    max_wave_speed[i] = vel_mag + sound_speed;
  }
 
}
 
template< typename T>
__global__ void compute_entropy_kernel(T * __restrict__ S,
                                       const T * __restrict__ p,
                                       const T * __restrict__ rho,
                                       const T gamma,
                                       const int n) {
 
  const int idx = blockIdx.x * blockDim.x + threadIdx.x;
  const int str = blockDim.x * gridDim.x;
 
  for (int i = idx; i < n; i += str) {
    // S = 1/(gamma-1) * rho * (log(p) - gamma * log(rho))
    T log_p = log(p[i]);
    T log_rho = log(rho[i]);
    S[i] = (1.0 / (gamma - 1.0)) * rho[i] * (log_p - gamma * log_rho);
  }
 
}
 
#endif // __FLUID_COMPRESSIBLE_OPS_KERNEL_H__