Monday, July 19, 2021

How to... define cylindrical anisotropic conductivity in Ansys Fluent (cyl-orthotropic)

Many of the problems that are modeled in CFD today concern multi-layer objects. It often happens that these  models have large sizes and thin layers. Due to this specificity, we have certain conduction properties in various directions of solid body. Drawing such models in the 1: 1 scale causes many problems, primarily related to the generation of a very large number of finite elements. Sometimes the computer hardware parameters do not allow us to perform such an analysis.


how to define layers in ansys fluent
Cyl-orthotropic in Ansys Fluent 

Saturday, July 17, 2021

How to... define quasi porous material in Transient Thermal (material combination)

 A very interesting option in newer versions of Ansys Workbench is defining materials consisting of several components.  It is especially useful because the program automatically updates the physical and thermal properties of the new defined mixture.  It is possible to create, for example, porous materials consisting of a solid and a fluid.


Wednesday, July 14, 2021

How to... simplify case when Your Fluent Structural FSI doesn't work ?

It often happens that we want to do a coupled analysis consisting of two CFD and Structural modules. The purpose of FSI analyzes is to set the thermal conditions that came out from CFD simulation to the Structural analysis as boundary conditions. In the module for mechanical calculations itself, we cannot set a heterogeneous temperature profile, therefore it is necessary to perform two analyzes in these cases as FSI. A very common problem in this type of analysis is a bad transfer of thermal conditions to the Structural module. The distribution of values is not the same as what we came out with CFD. Therefore, in these cases, you can simplify the analysis by adding one more Transient Thermal module from which the transfer of temperature distributions is burdened with a much smaller error.

how to perform fsi analysis
III stages for simplify FSI case

Tuesday, July 13, 2021

How to... fix error Floating Point Exception -Overflow in Ansys CFX ?

 Many times, during the implementation of numerical modeling, after completing the boundary and initial conditions and starting the solver we have to do with a sudden stop of the analysis and the appearance of an overflow message.  This is the most common type of error that occurs when performing CFD analysis.  In today's post, I would like to present two paths to minimize the appearance of this error.

How to fix error floating point exception overflow ansys
Most often  error in CFX 


Friday, July 9, 2021

How to... choose radiation model in Ansys Fluent

 Many times in numerical modeling we have a dilemma whether we have to take into account the radiation model, and if so, what exactly to choose.  

Types of radiation models ansys fluent
Which model of radiation to pick in Fluent

Thursday, July 8, 2021

How to... analyze and measure model in postprocessing CFX / Fluent Ansys

After many analyzes, we come to the conclusion that each elaboration of the results looks similar (sometimes identical).  Then it's time to diversify our report with new indicators and charts.  Ansys postprocessing offers many possibilities.  First of all, we can display our output with different configurations of contours, velocity vectors or isosurfaces.

How to separate data ansys workbench
Path to generate measuring  lines

Tuesday, July 6, 2021

How to... perform a temperature dependent analysis without an Energy Model Ansys Fluent

 There is often a need to model the gas flow in specific systems with a temperature other than 25 C. Then we include the Energy model in the standard modeling procedure. The number of subsequent models taken into account in our analysis significantly extends the computation time. This is mainly due to the fact that the program has to solve additional equations (in our case, equations related to heat transfer). If our goal is not the temperature distribution in the analyzed domains, then we can simplify the analysis by omitting the Energy model.

defining gas properties in Fluent
How to define gas properties in Fluent 

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