residual oscillation
 

Hello, I am studying enclosed convection in small cavity and I want to evaluate the influence of gas pressure on thermal plume developped by a heated wire at the bottom of the cavity. Under 5 bar results fit well with experience, but for higher pressure, residual values of continuity start to oscillate. Perhaps somebody could help me ? Thank you. Philippe

Re: residual oscillation
 

switch on unsteady solver

Re: residual oscillation
 

Ok, but do I use small time step (and it will take a long time) or a large step ? Thank you. Philippe

Re: residual oscillation
 

if you ust to large time step, it won't converge. you must compute by hand the time step you need. for instance t=(minimum cell size of your domain)/(maximum velocity you are guessing) I would use adaptive time stepping

Re: residual oscillation
 

I am just trying adaptative time step, thank you very much for your answer. Philippe

Re: residual oscillation
 

de rien