Thi3Dr8 generates an incompressible 3D homogeneous isotropic turbulent field for the initialization of NTMIX. Two turbulence spectra are available: Passot-Pouquet (pp) and Von Karman-Pao (vkp).
 

Output :

• gas data file at NTMIX format (file= "initturb")

Present Platform  :

• NEC SX5, Monoprocessor

Internal :
 

•      you need the cfft99.f file (performs multiple fast Fourier transforms)
•      example of makefile
•      to be modified inside the source :

Input data :

In mesh.inc :
1  NX+1
2  NY+1
3  NZ+1

If x_i is a periodic direction, the new dimension of the NTMIX restart file will be NX_i (NX_i +1 in the other cases).

During the execution of Thi3Dr8:
  1  idum (seed of the random numbers generator)
  2  dummy (dummy=1 <=> vkp=.true., else pp=.true.)
  3  xmin
  4  ymin
  5  zmin
  6  xmax
  7  ymax
  8  zmax
  9  dummy (dummy=1 <=> ignition=.true.)
10  Up (turbulent velocity)
11  Le (most energetic length scales)
12  Ld (dissipation length scales)
13  Dissip
14  Re

Note: Ld and Dissip are not taken into account in the case of a Passot-Pouquet spectrum.
 

Variant :

Thi3D :   -> dynamic allocation (falloc)
          -> "monoto3d" option to create a 3D turbulent field from a 1D laminar state (file="input"):
                                        rho3d(i,j,k)=rho1d(i)
                                        u3d(i,j,k)=u1d(i)+u_turb(i,j,k)*Y1d(i)
                                        v3d(i,j,k)=v_turb(i,j,k)*Y1d(i)
                                        w3d(i,j,k)=w_turb(i,j,k)*Y1d(i)
                                        Et3d(i,j,k)=Cp*Temp1d(i)/Gamma
                                                            +0.5*(u3d(i,j,k)*u3d(i,j,k)+v3d(i,j,k)*v3d(i,j,k)+w3d(i,j,k)*w3d(i,j,k))
                                        Y3d(i,j,k)=Y1d(i)
 

VKP spectrum :

vkp3D has to be executed before Thi3Dr8.

Contrary to the Passot-Pouquet spectrum, the choice of the parameters {Up, Dissip, Re, Ld, Le} for a Van Karman-Pao spectrum is not arbitrary. This quintuple is given by vkp3D for 2D and 3D configurations.
 
 

CERFACS versions: falloc, makefile.
(B. Cuenot)
 
 

Note author : O. Vermorel, IMFT, 2002

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