Problem with residual

aleman · April 8, 2014, 06:59

Hi, I am a naval engineer and work with Star ccm+ for simulate various hull.
I have a question: how can I reduced the residuals during the simulations?
Thanks for the responses!

me3840 · April 8, 2014, 09:55

You have a transient simulation, so reducing the residuals in total doesn't really mean anything. You just want to ensure they converge in each timestep.

Looking at your second picture you can see your gas-liquid interface is being diffused by the grid coarseness at the sides. You need to capture the interface with a good number of cells.

aleman · April 10, 2014, 16:44

thanks! I understood the problem!
I have another one problem: when I use refine field fuction for the mesh, the calculus run for many minutes, but not arrive to the conclusion with an error for the memory ram. why?
Thanks again!

me3840 · April 10, 2014, 18:08

Quote:

Originally Posted by aleman

thanks! I understood the problem!
I have another one problem: when I use refine field fuction for the mesh, the calculus run for many minutes, but not arrive to the conclusion with an error for the memory ram. why?
Thanks again!

I don't quite understand the question. Can you rephrase it? Can you copy-and-paste the error?

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April 8, 2014, 09:55		#2
me3840 Senior Member Join Date: Nov 2010 Location: USA Posts: 1,232 Rep Power: 24	You have a transient simulation, so reducing the residuals in total doesn't really mean anything. You just want to ensure they converge in each timestep. Looking at your second picture you can see your gas-liquid interface is being diffused by the grid coarseness at the sides. You need to capture the interface with a good number of cells.

April 10, 2014, 16:44		#3
aleman New Member Alessandro Join Date: Nov 2013 Posts: 2 Rep Power: 0	thanks! I understood the problem! I have another one problem: when I use refine field fuction for the mesh, the calculus run for many minutes, but not arrive to the conclusion with an error for the memory ram. why? Thanks again!