Simple vs Coupled which is best for airfoil

harshu9358 · September 23, 2018, 00:25

hello all,

I'm trying to simulate airfoil. I'm using pressure-based solver. the question is does using simple or simplec method can change the result from the result we get from using coupled solver. and if i use coupled solver there is an divergence detected error which i'm not facing using simple at higher angle of attacks.

Thankyou, waiting for your answers

subhankarnits · September 23, 2018, 00:31

In my simulation of open channel flow, I'm also facing the same problem. For simple or simplec it is converging but for coupled solver it not converged yet. I will suggest you use piso. I heard that piso gives stable solution.

LuckyTran · September 24, 2018, 16:26

They should all give very similar results if the solution is converging.

You have to tinker and play with a lot of numerical settings. The default settings do not guarantee convergence for all possible problems in the universe. Of course the quality of your initial guess also influences things. My recommendation, use whatever works.

September 23, 2018, 00:25	Simple vs Coupled which is best for airfoil	#1
harshu9358 New Member harsha vardhan Join Date: Sep 2016 Posts: 1 Rep Power: 0	hello all, I'm trying to simulate airfoil. I'm using pressure-based solver. the question is does using simple or simplec method can change the result from the result we get from using coupled solver. and if i use coupled solver there is an divergence detected error which i'm not facing using simple at higher angle of attacks. Thankyou, waiting for your answers

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September 23, 2018, 00:31		#2
subhankarnits Member subhankar das Join Date: Jul 2018 Posts: 32 Rep Power: 8	In my simulation of open channel flow, I'm also facing the same problem. For simple or simplec it is converging but for coupled solver it not converged yet. I will suggest you use piso. I heard that piso gives stable solution.

September 24, 2018, 16:26		#3
LuckyTran Senior Member Lucky Join Date: Apr 2011 Location: Orlando, FL USA Posts: 5,704 Rep Power: 66	They should all give very similar results if the solution is converging. You have to tinker and play with a lot of numerical settings. The default settings do not guarantee convergence for all possible problems in the universe. Of course the quality of your initial guess also influences things. My recommendation, use whatever works.