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Failed to find a solution. Maximum number of Newton iterations reached. Returned solution is not converged.''

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Hi,

I am trying to simulate Air flow through an extraction chamber. The file is too large to be attached here.. my inlet pressure is 1 pa and outlet is about -2 pa. It is the concept of suction which is being used.
I carried out the simulation first with fluid as water, density of 1000kg/m3 and Viscosity of 0.001 Pas with Laminar Flow as physics control.

But as my real case is with air, if i put fluid properties as density 1.24 and viscosity 0.0000195 (of air at 20C) keeping rest of the things same. My solution does not converge. Can someone please help me out, as

I get an error of "Failed to find a solution.
Maximum number of Newton iterations reached.
Returned solution is not converged.''

2 Replies Last Post Jan 18, 2017, 4:19 a.m. EST

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Posted: 8 years ago Jan 17, 2017, 2:37 p.m. EST
Try with finer mesh or use study extension for outlet pressure value. Define a parameter for outlet pressure with initial value ZERO. Then ramp down the pressure from zero to -2. Hope this will help.
Try with finer mesh or use study extension for outlet pressure value. Define a parameter for outlet pressure with initial value ZERO. Then ramp down the pressure from zero to -2. Hope this will help.

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Posted: 8 years ago Jan 18, 2017, 4:19 a.m. EST
I did not fully understand what you mean here Sir, Could you explain it a little more in detail. I actually have a calculated(approximate) velocity value at my outlet for the case which I am solving. But even if I put the inlet condition of pressure at atmospheric and outlet as velocity of 1.7 m/s it gives the same error.

The 1 pa and -2 pa was just a test. My actual case has an inlet pressure of atmospheric pressure and outlet is some kind of lower pressure.
I did not fully understand what you mean here Sir, Could you explain it a little more in detail. I actually have a calculated(approximate) velocity value at my outlet for the case which I am solving. But even if I put the inlet condition of pressure at atmospheric and outlet as velocity of 1.7 m/s it gives the same error. The 1 pa and -2 pa was just a test. My actual case has an inlet pressure of atmospheric pressure and outlet is some kind of lower pressure.

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