Convergence Problem in k-e model

Rajeev Kumar Singh

Hi Everybody !

I am simulating flow of liquid steel inside a tundish. Trough shaped vessel of 2910 x 500 x 700 mm dimensions. When I run different cases of it with 500 , 400 or 300 mm height instead of 500mm I find the residuals behaving in a different manner. Sometimes it converges smoothly with reduced relaxation parameters. sometimes it does not. I used PISO for pressure velocity coupling. Why is it that sometimes I get a convergence problem and there is always a mass imbalance of order of 10-3 when the inlet mass is 10 kg/s approximately. Can anyone throw some light where I am making a mistake.

Thanks in advance

Rajeev