[cathie]

Hello all,

I am working on a project to simulate the heat transfer in gyroid cell involving sCO2 at two different pressure and temperature (hot and cold fluid). Dimension of the each cell is only 5mm and thickness is 0.5mm. I impose periodic boundaries on all four sides and even though solution converge after long time there is always a small oscillation in the pressure plot. Even though transcient solution reduces this to some extent there is still some instabilities. I have checked without periodic boundaries but still there is this numerical issues. The velocity is in the range of 0.2 for cold fluid and 1 m/s for hot. Pressure of and temperature is in the range of 80 - 250 bar and 300-500°C. I use SST model with low Re correction since Re is around 5000. I imagine the combination of complex geometry + complex fluid @ high pressure. There was not much support from the Ansys local support hence posting it here since we have many experts here from diverse field. Any help or suggestions would be appreciated.

thanks and regards