1. Set up the parameter 'Cs' in grid.f as you want.

2. Run the grid.f (run grid). This will generate grid.e. Type grid.e and three files will be created. These are:

Channel.grd: New grid system

 Channelold.grd: Old grid system

 Channelp.grd: New grid system which is expressed in wall unit

3. Run the convert.f. You will get the new three-dimensional initial data. (*3D_NEW.*)

4. Set up the parame.ter

N1: Number of grid points in the x direction

N2: Number of grid points in the y direction

N3: Number of grid points in the z direction

RE: Reynolds number based on bulk velocity and the half width of the channel

ALX: domain size in the x direction

ALZ: domain size in the z direction

INCODE: Set up the domain size inside the main program(ch.f). '0' means that the domain size is determined by ALX and ALZ in "parame.ter".

"1" means that the domain size is designated inside the main program (see the subroutine "SETUP" in ch.f).

NTST: Number of time step

VPER: Level of random fluctuations. ex) VPER=0.2 means that we impose the random fluctuations to the initial flow field as 20% of bulk mean velocity.

DT: Interval of time step

IDTOPT: Option for optimal time step. If this is 1, CFL number is restricted by CFLMAX in "parame.ter".

CFLMAX: Maximum CFL number. It is valid when IDTOPT is 1.

NWRITE: Write option. If it is 1, 3D flow field will be written every "NPRN" th time step.

NPRN: Interval of writing 3D flow

NREAD: Read option. If it is 1, the simulation is restarted from the previous 3D flow field.

IAVG: Averaging option.

INSF: Instantaneous flow field option. If it is 1, instantaneous flow field will be written every "NINS" th time step.

NINS: Interval of writing instantaneous flow field.

GAMMA: Weighting factor of v velocity at the wall. V_wall(I,K)=-GAMMA*V(I,NY,K)

 NY: Detecting position of v control (y⁺~15).

5. Run the ch.f. Then type ch.e. Look at Extra Notes section.

6. Monitor the time history files of Re_tau (WALLSS.plt or PRESG.plt), volume flow rate (FLOW.plt) and CFL number (CFL.plt).

 

Extra Notes

ch.e > filename & - here the & sign makes ch.e run in the background.

nohup ch.e > filename & - here nohup stands for "no hang up". This command allows you to exit the program and solar will continue to process in the background.

top control - will show the state of the program.

kill -9 PID - this will stop the program with the given PID number.