#I have a message "Turbulent viscosity limited to viscosity ratio of 1.000000e+05 in xxx cells.How can i fix this error message in ansys fluent.

My project is temperature analysis of a double pipe helical type heat exchanger using water as fluid.

Hello everyone!

I'm doing a simulation in fluent and at some point, usually after the first 15 steps, the error appears:

Divergence detected in AMG solver: temperature

Divergence detected in AMG solver: temperature

Error at host: floating point exception

Error at Node 0: floating point exception

Error at Node 1: floating point exception

===============Message from the Cortex Process================================

Compute processes interrupted. Processing can be resumed.

==============================================================================

Error: floating point exception

Error Object: #f

I'm compiling a UDF file, Time transient, convergence criterion relative, number of time steps 1000, able Specified Operating Density like zero kg/m^3. The mesh is refined in the best possible way.

What is the reason behind it?

Best regards.

I am solving conjugate heat transfer problem in Ansys Fluent. The system is like a cylinder with 4 layers of solid (one over other) and fluid inside it. The the inside surfaces of the solid has radiation. As one of the layer is too thin, I am getting very poor skewness for this particular layer. When I am solving, I am getting "Temperature limited to 1.000000e+00 in x cells of zone 1 in domain 1"

This results in very unrealistic temperature distribution in the solid.

The problem is transient. I am using S2S model for radiation and K-e for turbulence. I am using adaptive time stepping.

Please suggest any solution.

Hi, I simulate a wind turbine using Ansys fluent (3D simulation). My objectives are to study the rotor aerodynamic performances and to visualise the fluid flow around it. In the calculation step, the continuity residual couldn’t reach a value below than 10^_3.

How can I solve this problem? And what is the acceptable value of the continuity residual?

I am doing a 3D steady simulation of a wind rotor using Ansys Fluent. In order to have a y+ of 1, I created 10 inflation layers using total layer thickness method, and I started a first simulation. After calculation, I want to check the y+ value obtained but I don't know how can I do it ?

Hi,

I have a problem witch have three type of boundary conditions, pressure inlet, pressure outlet and wall, it is a Convergence-Divergence (C-D) Nozzle.

after start calculate in Fluent, this warning is appear:

turbulent viscosity limited to viscosity ratio of 1.000000e+05 in 549537 cells

I was changed turbulent model, refine mesh and checked boundary condition, but this warning did not disappear.

In addition, after 2000 iteration, suddenly Fluent was stop and exit run without any message. i am so confused about this problem. can anyone help me?

I am a green hand about CFD ant the software-ANSYS fluent. There is a question for me. That is, i don't know how to select wall function for a particular project.

So, are there some classical books and references for guiding users to select certain fuction for their project?

THANK YOU VERY MUCH!

What is the best value of Maximum Aspect Ratio in Ansys Fluent? 

Hello Friends,

I am trying to simulate a 3D LPT blade using hybrid meshing in fluent. I made the mesh by merging two meshes in ICEM. The mesh around the blade is made using blocking and other is tetra mesh. Then i merged it at a common interface.

When i set all the boundary conditions and try to initialize the case it shows

Is this becoz of mesh or some scheme. I am using transition model k-kl-w.