I have difficulty in the simulation of natural convenction.The field is special:it is rather high ,but it has a small width(in cylinder coordinate ).Which buoyancy model should I choose? Which scheme Should I choose?How can I modify the Grid?

tony,

Natural convection: try density differnce bouancy model. Have a look at some of the library cases for a start at selecting the required parameters.

Grid: In VR Veiwer, using the toolbar, select the grid where you want refinement and insret into the popup the number of cells you want.

Read the tutorials in POLIS: it gives a step by step guide to setting these problems up.

Leon