[jonas9038]

Hello, im currently doing an starccm+ course at my university and i need help with a simulation. The attached pictures show the simulation.
Air streams through pipes onto a solid modell. The solid modell has a constant temperature of 600C on the inside. The aim is to simulate the temperature gradient inside the solid and the air velocity around the modell.

[jonas9038]

Some more pictures.


My problem is that residuals are not converging and in my opinion my continua settings and boundary settings need an optimization. Can somebody tell me what to improve or to change? Thanks for your ideas!

[fluid23]

It looks to me like you are trying to converge an unsteady flow using a steady solver. Mesh improvements may help, you can always track down high residuals and try refining the mesh.

I would also suggest switching to implicit unsteady with a suitable time step. Your residuals should converge within each step.

[jonas9038]

Thanks for your answer. What would be a suitable time step?