fourier     !! treatment of u in x direction
 fourier     !! treatment of u in y direction 
 cos         !! treatment of u in z direction
 fourier     !! treatment of v in x direction 
 fourier     !! treatment of v in y direction 
 cos         !! treatment of v in z direction
 fourier     !! treatment of w in x direction 
 fourier     !! treatment of w in y direction 
 sin         !! treatment of w in z direction
 fourier     !! treatment of s1 in x direction 
 fourier     !! treatment of s1 in y direction 
 sin         !! treatment of s1 in z direction
 fourier     !! treatment of s2 in x direction 
 fourier     !! treatment of s2 in y direction 
 cos         !! treatment of s2 in z direction
 fourier     !! treatment of phi in x direction 
 fourier     !! treatment of phi in y direction 
 cos         !! treatment of phi in z direction