hi.

can you (in few words) explain me how to use viscous models. I mean which model is proper for which problem (if it is possible to descibe in few words). I know that some of them are more time and CPU consumption. Which are the best for use with problems involving mass and heat transfer.

thank you for help

u should describe ur problem with more detailes ... what's ur geometry of ur problem .. do u use heated walls?

1-if you have a rotational flow you must use k-omega. 2-if you have a simple flow (with a few rotation or without) :k-epsilon,rng...... 3-if you want to have the precistion you must use :rsm

in conclusion ,you must use the model of turbulence for two condition: 1-good results.

2-optimal(few cpu). best regards

to saeed: I have solar radiation, mass and heat transfer, no moving parts (no rotating parts), just flow in rectangular chanel (pipe). Velocities of fluid from 0.001 m/s to 0.5 m/s. No chemical reactions

to gladiatior: thanks. This short quide is very, very, very good and useful. Meybe you know a website or have any pfd with such (simple language,good description ) tutorials of turbulence

thanky you both of you guys