[u k jha]

high i am creating the mesh in th icem cfd how much quality is preferred for the simulation

[PSYMN]

You need to give more details... What is the mesh type and what is the solver?

Hexa solvers usually want a min angle of 9 to 18 degrees, hexa determinant should be above 0.1 or 0.2. Warpage and other factors should also be looked at.

Tetra mesh should have an "ICEM CFD quality" of greater than 0.2, but some cells below that are ok provided they are not in critical areas.

The ICEM CFD "Quality" metric is pretty harsh on Prism mesh (divides the prism into three virtual tetras and takes the worst normalized circumsphere ratio of the three), but usually Prisms of over 0.01 will run.

They just added a TGrid Skew quality metric to ICEM CFD 12.0 that matches TGrid exactly, if that is what you are looking for (remember TGrid is inverted so 0 is good and 1 is bad)

Of course your solver matters also... Some solvers are very tolerant of bad internal angles, but are sentitive to volumetric change. Others are the other way around. Some would prefer poor prisms to any pyramids, others would prefer a few decent pyramids rather than poor prisms.

I recomend checking the requirements with your solver's documentation. Keep in mind that there is usually a decent factor of safty there so they can blame the mesher if things don't converge.