Assessing Residual Plot

danisnug · January 5, 2019, 19:47

Good day,

I'm currently running a HVAC flow simulation inside bus cabin, the residual plot graph tends to converge but my graph is unlike the other. Other graph has smooth converging line while my graph has fluctuating line. Could you help me assessing what are the problems with my simulation? Provided here is an image of my residual plot.

Thank you

RaiderDoctor · January 6, 2019, 15:15

Hey danisnug, welcome to the forum!
So, you're asking a question about convergence. Unfortunately, there really isn't a clear-cut answer as to whether your simulation is "good" or not. I'd recommend reading this (https://www.engineering.com/DesignSo...nvergence.aspx) to get you started. Then, I'd check out what some of the other smart dudes on this forum have posted (Convergence).

Finally, I don't think you're going to get much help on your problem, with the way you asked your question. Fluent is an immensely complicated program with a lot of customization options. When you ask a specific question, you need to post the specifics of your setup. For instance, is your case transient or steady-state, is there mesh motion, does something happen every few iterations that might cause the spike in residual activity, etc. Screenshots of your fluid domain, mesh, and options you selected are a big plus. That isn't necessarily an invitation to start posting now, I think the info I provided might help you better understand the nature of your simulation as is.

Good luck!

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January 6, 2019, 15:15		#2
RaiderDoctor Senior Member Join Date: Dec 2016 Posts: 152 Rep Power: 10	Hey danisnug, welcome to the forum! So, you're asking a question about convergence. Unfortunately, there really isn't a clear-cut answer as to whether your simulation is "good" or not. I'd recommend reading this (https://www.engineering.com/DesignSo...nvergence.aspx) to get you started. Then, I'd check out what some of the other smart dudes on this forum have posted (Convergence). Finally, I don't think you're going to get much help on your problem, with the way you asked your question. Fluent is an immensely complicated program with a lot of customization options. When you ask a specific question, you need to post the specifics of your setup. For instance, is your case transient or steady-state, is there mesh motion, does something happen every few iterations that might cause the spike in residual activity, etc. Screenshots of your fluid domain, mesh, and options you selected are a big plus. That isn't necessarily an invitation to start posting now, I think the info I provided might help you better understand the nature of your simulation as is. Good luck!