Random number

[selim]

Hi,

I want to implement a time dependent boundary condition in compressible Navier-Stokes equation which is a random function.

Here is how I used the function in the .sif file in the related inlet boundary;
------------------------------------------------------------------
Boundary Condition 3
Name = "Constraint3"
Target Boundaries(1) = 3
Velocity 1 = Variable "Timestep"
MATC "0.2+0.01*rand(tx)"
Temperature = 293
End
---------------------------------------------------------------------


Here is the error part of the log file:

-----------------------------------------------------------------------------------------
Solver input file error: MATC ERROR: Zeros: invalid size for and array
-------------------------------------------------------------------------------------------

Any suggestions,
Thanks a lot,
Selim

[raback]

Hi Selim,

The matc function rand expects the size of the matrix as an argument (an integer not a real as the argument tx). So try with rand(1) instead.

BR, Peter