convergence unsteady state

cfdhydraulic · March 24, 2012, 11:38

Hi Banty,
look at this... 87 seconds and the tanks still full with air and pressurized... no way...

I started with time step 0.1 then 0.5... then 1 then 5... nothing... results are pretty much the same

Please see pictures of parameters, residuals and results...

I do appreciate your help!
Thank you

banty · March 28, 2012, 14:31

Hello,

something wrong with the solver setting or mesh or even in physical problem modeling because solution is not converging (residuals ~ 10^-1). Would u once check with very fine mesh.

cfdhydraulic · March 29, 2012, 15:50

mesh is ok because I have a 97% of element quality, low skewness, and fine aspect ratio.
A finest mesh will make me require a parallel process...
have you ever tried to solve a discharging process?

if you want to you can design a 52ft high and 12ft diameter. Discharge air from 150psi to a 42" line

Thank you Banty

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March 28, 2012, 14:31		#22
banty Member banty Join Date: Mar 2012 Posts: 52 Rep Power: 14	Hello, something wrong with the solver setting or mesh or even in physical problem modeling because solution is not converging (residuals ~ 10^-1). Would u once check with very fine mesh.

March 29, 2012, 15:50		#23
cfdhydraulic Member andres Join Date: Sep 2010 Posts: 44 Rep Power: 16	mesh is ok because I have a 97% of element quality, low skewness, and fine aspect ratio. A finest mesh will make me require a parallel process... have you ever tried to solve a discharging process? if you want to you can design a 52ft high and 12ft diameter. Discharge air from 150psi to a 42" line Thank you Banty