time step and inner iteration loop
 

Hello all, Actually I am new to CFD. am using CFDesign to do a transient analysis for heating and cooling of a surface by forced convection using water. I tried using 10 iteration loops and it always gives divergence. I once tried with 2 iterations and it was kindoff stable. Can anyone tell or refer me to some nice explanatin of this. I want to know if it matters and why and how?

thank you

Re: time step and inner iteration loop
 

use smaller time step

Re: time step and inner iteration loop
 

well you have not defined your case very clearly . you have not even mentioned that you are running in unsteady mode :D by the way, things that you have to consider in unsteady mode calculations are: 1.physical time step. which depends on many aspects. 2. inner iteration 3. and the number of outer iteration in your case that you are getting divergence with 10 outer iteration I guess your number of inner iteration is not enough, each inner iteration should converge at first. the other thing maybe your physical time step. decrease it...