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Rotating machinery not converging
Posted Jul 15, 2010, 12:03 a.m. EDT 1 Reply
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Hello
I am working with a rotating impeller in a cylindrical tank (chemical engineering module/rotating machinery). This is a 2D model, so it looks like a cross in a circle. Here are the parameters I'm using:
rho (density) = 1000 kg/m^3
eta (viscosity) = 1e-2 Pa*s
rpm = 14 1/min
If I increase the density or the rpm, or if I decrease the viscosity, then the model does not converge, saying that it didn't find consistent initial conditions. Eventually, I need to model a fluid with density of about 2000 kg/m^3, viscosity of 1.2e-3 and rpm of about 500.
Any suggestions?
Thank you!
Sylvana
I am working with a rotating impeller in a cylindrical tank (chemical engineering module/rotating machinery). This is a 2D model, so it looks like a cross in a circle. Here are the parameters I'm using:
rho (density) = 1000 kg/m^3
eta (viscosity) = 1e-2 Pa*s
rpm = 14 1/min
If I increase the density or the rpm, or if I decrease the viscosity, then the model does not converge, saying that it didn't find consistent initial conditions. Eventually, I need to model a fluid with density of about 2000 kg/m^3, viscosity of 1.2e-3 and rpm of about 500.
Any suggestions?
Thank you!
Sylvana
1 Reply Last Post Jul 15, 2010, 7:28 a.m. EDT
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Posted:
1 decade ago
is it 2D axial symmetry? Using turbulence model? If not: Try k-eps
Higher density, higher rpm, lower viscosity leads to higher Re-Number -> turbulence increases.
Anyway, a denser mesh is always a good answer to not-reaching-convergence-problems
Higher density, higher rpm, lower viscosity leads to higher Re-Number -> turbulence increases.
Anyway, a denser mesh is always a good answer to not-reaching-convergence-problems