
   import numpy as np
   import sys


########### section 1 choice of differencing scheme ###########
   scheme='h'  #hybrid
   scheme_turb='h'  #hybrid upwind-central 

########### section 2 turbulence models ###########
   cmu=0.09
   kom = True
   c_omega_1= 5./9.
   c_omega_2=3./40.
   prand_omega=2.0
   prand_k=2.0
   kappa = 0.41

########### section 3 restart/save ###########
   restart = True
   save = True

########### section 4 fluid properties ###########
# re = 2*u_wall*2h/viscos = 4/viscos 
   viscos=4/5200

########### section 5 relaxation factors ###########
   urfvis=0.5
   urf_vel=0.5
   urf_k=0.5
   urf_p=1.0
   urf_omega=0.5

########### section 6 number of iteration and convergence criterira ###########
   maxit=3000
   min_iter=1
   sormax=1e-7

   solver_vel='lgmres'
   solver_pp='lgmres'
   solver_turb='lgmres'

   nsweep_vel=50
   nsweep_pp=50
   nsweep_turb=50
   convergence_limit_u=-1e-6
   convergence_limit_v=-1e-6
   convergence_limit_k=-1e-6
   convergence_limit_om=-1e-6
   convergence_limit_pp=5e-4

########### section 7 all variables are printed during the iteration at node ###########
   imon=0
   jmon=10

########### section 8 save data for post-processing ###########
   vtk=False
   save_all_files=False
   vtk_file_name='bound'

########### section 9 residual scaling parameters ###########
   uin=20
   resnorm_p=uin*y2d[1,-1]
   resnorm_vel=uin**2*y2d[1,-1]


########### Section 10 boundary conditions ###########

   cyclic_x=True
# boundary conditions for u
   u_bc_west=np.ones(nj)
   u_bc_east=np.zeros(nj)
   u_bc_south=np.zeros(ni)
   u_bc_north=np.zeros(ni)

   u_bc_west_type='n' 
   u_bc_east_type='n' 
   u_bc_south_type='n'
   u_bc_north_type='n'

# boundary conditions for v
   v_bc_west=np.zeros(nj)
   v_bc_east=np.zeros(nj)
   v_bc_south=np.zeros(ni)
   v_bc_north=np.zeros(ni)

   v_bc_west_type='n' 
   v_bc_east_type='n' 
   v_bc_south_type='d'
   v_bc_north_type='d'

# boundary conditions for p
   p_bc_west=np.zeros(nj)
   p_bc_east=np.zeros(nj)
   p_bc_south=np.zeros(ni)
   p_bc_north=np.zeros(ni)

   p_bc_west_type='n'
   p_bc_east_type='n'
   p_bc_south_type='n'
   p_bc_north_type='n'

# boundary conditions for k
   k_bc_west=np.zeros(nj)
   k_bc_east=np.zeros(nj)
   k_bc_south=np.zeros(ni)
   k_bc_north=np.zeros(ni)

   k_bc_west_type='n'
   k_bc_east_type='n'
   k_bc_south_type='d'
   k_bc_north_type='d'

# boundary conditions for omega
   om_bc_west=np.zeros(nj)
   om_bc_east=np.zeros(nj)

   xwall_s=0.5*(x2d[0:-1,0]+x2d[1:,0])
   ywall_s=0.5*(y2d[0:-1,0]+y2d[1:,0])
   dist2_s=(yp2d[:,0]-ywall_s)**2+(xp2d[:,0]-xwall_s)**2
   om_bc_south=10*6*viscos/0.075/dist2_s

   xwall_n=0.5*(x2d[0:-1,-1]+x2d[1:,-1])
   ywall_n=0.5*(y2d[0:-1,-1]+y2d[1:,-1])
   dist2_n=(yp2d[:,-1]-ywall_n)**2+(xp2d[:,-1]-xwall_n)**2
   om_bc_north=10*6*viscos/0.075/dist2_n

   om_bc_west_type='n'
   om_bc_east_type='n'
   om_bc_south_type='d'
   om_bc_north_type='d'

   return 


