RANS_setup.f90

!-----------------------------------------------------------------------------------!
!
!   PROGRAM : RANS_setup.f90
!
!   PURPOSE : Setup the 1D turbulent channel flow for RANS model
!
!                                                                 2016.11.17 K.Noh
!
!-----------------------------------------------------------------------------------!

        SUBROUTINE SETUP

            USE RANS_module,                                                    &
                ONLY : Ny, del, dy, Re_tau, nu, u_tau,                          &
                       Cm, Ce1, Ce2, Sk, Se, alpha, beta, itmax, resi, tol

            USE RANS_module,                                                    &
                ONLY : U, U_exac, U_new, Y, k, k_new, dis, dis_new, nu_T, prod

            IMPLICIT NONE
            INTEGER :: i,j

            !-----------------------------------------------------------!
            !                 Constants for simulation
            !-----------------------------------------------------------!
            itmax = 10000000       ! maximum interation number
            resi = 0               ! criteria for convergence
            tol = 1e-12            ! tolerance for convergence

            Ny  = 360              ! the number of grid cells
            del = 1                ! the channel-half height
            dy  = (2*del)/Ny       ! grid size

            Re_tau = 180           ! Reynolds number based on friction velocity
            nu     = 3.5000e-4     ! Kinematic viscosity of reference data
            u_tau  = Re_tau*nu/del ! Friction velocity

            !-----------------------------------------------------------!
            !                   Constants for k-e model
            !-----------------------------------------------------------!
            Cm  = 0.09
            Ce1 = 1.44
            Ce2 = 1.92
            Sk  = 1.0
            Se  = 1.3

            !-----------------------------------------------------------!
            !                     Relaxation factors
            !-----------------------------------------------------------!
            alpha = 0.1
            beta  = 0.4

            ALLOCATE( U(0:NY),U_new(0:Ny),U_exac(0:Ny),Y(0:Ny),prod(0:Ny) )
            ALLOCATE( k(0:Ny),k_new(0:Ny),dis(0:Ny),dis_new(0:Ny),nu_T(0:Ny) )

            !-----------------------------------------------------------!
            !                      Initial Conditions
            !-----------------------------------------------------------!
            DO j = 0,Ny
              Y(j)        = j*dy
              U(j)        = 0
              k(j)        = 0.1000
              dis(j)      = 0.0300
              nu_T(j)     = 0
              prod(j)     = 0

              k_new(j)    = 0
              U_new(j)    = 0
              dis_new(j) = 0
              U_exac(j)   = -(nu/(2*del))*(Re_tau/del)**2 * Y(j) * (Y(j)-2*del)
            END DO

        END SUBROUTINE SETUP