Report averages of quantities on (lists) of surfaces in a file versus time in transient runs
|Users wanted to be able to record in a file in a spreadsheet format averages of various quantities versus time in transient runs.
They have as input a list of surfaces; on each of these surfaces,...
DEFINE_ADJUST UDF for the parallel solver
|Additional code is sometimes required to make a UDF work in parallel. One example is a DEFINE_ADJUST macro for calculating a mass weighted average or area weighted average of one or more flow...|
FLUENT - Text User Interface (TUI) commands for Tecplot export
|How to use TUI commands in the Execute Command panel to export data from FLUENT to Tecplot. In particular, how to specify all zones and several scalars.
To produce a tecplot file named...
FLUENT - VOF to model draining tank, swirling liquid, vortex at the drain drain.
|It is possible to model a draining tank filled with a
swirling liquid, and to capture the vortex that forms at the drain. The
goal was to pinpoint the time at which the first gas reaches
FLUENT 6 - Import 2d FLUENT 4 euler-euler data file to FLUENT 6
|Customer would like to continue in FLUENT 6 running an unsteady Euler-Euler FLUENT 4 calculation
that took several weeks to converge.
That is to say, he would like to import FLUENT 4 data into...
FLUENT - How to define your own turbulent thermal conductivity, C_K_T
|The UDF macro DEFINE_PROPERTY allows you to only modify laminar material properties.
When you do a turbulent simulation, FLUENT will always compute a turbulent thermal conductivity and add it to...
FLUENT - Tips for converging a highly compressible case using the segregated solver
|This solution contains a suggested procedure to converge highly compressible flow cases with the segregated solver.
-use incompressible (constant density)
-use default limits (Solver->...
FLUENT - A possible procedure for modeling the soaking condition in automotive underhood simulations
|The soaking condition would be the most challenging phase of the underhood simulation. Natural convection problems in general are highly unstable, because of the non-linearity due to strong...|
How can I reuse the results from a previous Fluent run to initialize my current Fluent calculation
|File interpolation can be used to utilize the results from a previous Fluent run to initialize the new run. This will help reduce the computation time. To do this, you will write out an...|
Face temperatures F_T(face,thread) are not available in UDF for interior faces. If required, it should be reconstructed.
|The UDF example reconstructs the face value based on cell temperature and cell temperature gradient stored on each side of the face.
This value is copied in UDM-0 in each cell located on each side...
How to create a moving 'fixed value' in FLUENT?
|A fixed value can be imposed via a source term and source term can depend on time. In this way it's possible to move a 'fixed value' around the domain during the simulation.
The question becomes...
Simulation of high temperature flame, over predicts the temperature than expected, what can be done to get a realistic temperature field?
|Global reaction mechanisms with one or two steps inevitably neglect the intermediate species. In high-temperature flames, neglecting these dissociated species may cause the temperature to be over...|
How can I record the DPM particles for individual size groups?
|You can record the particles for individual size groups by the following way.
Display-> particle Tracks
Report Type : Step by step
Report to : File
Color by : Particle variables (Particle...
I need to give temperature profile BC on a wall in ANSYS FLUENT. But the data points is such x, y, z coordinates of surface is not given but the variation with one of the axis is given. Without going for a UDF how can I get this profile on to the boundary?
|You can try the following procedure:
1. Curve fit the data
2. Create a custom field function using the equation
3. Do not give any BCs. Patch the whole domain with this custom field...
What gradient options is best with shell conduction zones in Fluent?
|Least Square Cell Based is the best if you want to accurately predict temperature on shell conduction zones.
Green Gause Node Based is the next option. The problem with node-based is that it...
I have a conjugate heat transfer problem in FLUENT 12. The energy residuals do not converge. What could be the cause and how to converge it?
1. Poor mesh quality: high size change, and/or high skewness, and/or coarse mesh
2. high jump in thermal conductivity
3. invalid boundary conditions
4. improper mesh...
How can we specify both spatial and temporal temperature profile on a wall zone?
In some heat transfer simulations, user will want to impose a temperature profile on a given wall zone that is varying both spatially and temporally. That is, at different times, the spatial...
How to compute the integral of a variable along a line using UDF in FLUENT?
|Line surfaces in FLUENT have area in 2d and 2d-axi but not in 3d, so currently integrals on line surfaces are zero.
This solution provides a sample User Defined Function (UDF) that shows how to...
How can we read the experimental/tabulated values of material properties or profiles using a UDF?
|FLUENT provides for a variety of methods for specifying material properties, including polynomial functions, piece-wise linear functions, etc. User-defined functions can also be used to specify...|
Can you give me some basic guidance on modeling droplet evaporation in FLUENT 12?
|Many users setup a droplet evaporation case in FLUENT and use default settings for material properties for the droplet. This is not correct as those are just placeholders. It is important to note...|
How can I compute the heat transfer coefficient in CFD-Post?
|In CFD-Post, under File->Export, export Temperature and Heat Flux to a .csv file using the desired surface on which you want to calculate the HTC.
Set Boundary Values to Hybrid so that...
In CFD-Post, how can we quickly create an animation of a transient problem, e.g. temperature contours on a slice moving through the time?
|See the PDF below:
How can I get cell values of temperature in CFD-Post?
How to resolve warning message involving the temperature limits?
|There are two main causes for this: shell conduction initialization and reacting flow/heat transfer issues.
If you are using Shell conduction, you must patch the shell zones using the...
How can I suppress the warning messages about reversed flow at certain boundaries or regarding limits on certain variables such as temperature or turbulent viscosity?
These warning messages could indicate potential errors or inconsistencies in your problem definition within FLUENT. In other cases, they may appear only during the early convergence stages of...