I tried to get the solution for the supersonic flow over a flat plate. After about 700 iterations, my horizontal velocity started turning negative towards the trailing edge and solution became imaginary.

Can anybody please suggest the mistake...

Years ago, I solved this same problem, reduce cell size to around 0.01 mm in the flow direction (you can have more than that in the normal direction) and the corresponding time step

>reduce cell size to around 0.01 mm

What if the flat plate is 0.02 mm long? Have you heard of non-dimensionalized variables?

and you, have you ever spent 3 month writing a C-programme to solve this problem? and that was 15 years ago, learn to be modest?

[archeoptyrx]

I will try for it . My cell size is 1.42*10-7 . I have the same problem. Plate length is .01mm with 70*70 grid points.

The code seems to work good results for M=4 . for M>4 it fails and gives me imaginary solutions .

Does increase in Velocity has some effects on the grid ?

Should i increase the grid points to 80*80 ?
Any suggestion will be of great help .

Thanks

[ufocfd]

Originally Posted by Nikhil
;50337

I tried to get the solution for the supersonic flow over a flat plate. After about 700 iterations, my horizontal velocity started turning negative towards the trailing edge and solution became imaginary.

Can anybody please suggest the mistake...

Maybe you have a sub-sonic outlet boundary, and you need to change it to supersonic boundary type ?

[archeoptyrx]

The outlet is just an extrapolated value from the interior points . So i think thats not a problem