msh file format for Fluent
These notes are not official documentation, and technically the msh file
format is NOT formally supported. However this document should serve in providing
instructions for how to...
FLUENT 6 - How to Implement Brownian Motion With variable Cunningham Correction Factor
|When the default Brownian motion of FLUENT is used in DPM it assumes a constant Cunningham correction factor. But because of the pressure drop across the orifices, the Cunningham might not be a...|
Tips for successfully modeling cavitation flows in rotating equipment
|Cavitation in rotating equipment (e.g. pumps) is an important industrial problem. Fluent 6.1 has a cavitation modes that can be used with rotating reference frames to model cavitation in pumps....|
FLUENT 6 - Converging a VOF mould filling simulation
|Converging VOF solutions may be challenging when the ratio of viscosity of the two fluids is far from 1.0.
Mould filling is a typical example of this problem. The injected material may have a...
conservation of total_enthalpy and total_energy
|Following conclusions based on thermodynamic definitions could be useful when checking for conservation of total_energy or total_enthalpy in a system.
Enthalpy = h = Internal_Energy...
Effective Strategy for ensuring convergence using FLuent's Fan Model
|If we switch on the fan model at the start so that it computes the Pressure Jump
from a fan curve, it is found that the solution diverges
after sometime and it predicts unreasonable mass...
Calculation fails with "fix" option enabled for a velocity component - a workaround
|The "fix" option in the Fluid BC panel permits you to fix a solution variable in a fluid zone.
In some cases, if a velocity component is fixed, the pressure correction equation will fail,...
POLYFLOW - Flow case with full slipping and inflow (constant normal force) may fail
|When defining a flow case (extrusion or not) with inflow calculation based on constant normal force and involving full slipping, the calculation may diverge.
This may also happen with prior...
Interrupting the fluent simulation when field variable exceeds any user-defined limit
|Sometimes a particular flow variable (Pressure, velocity, temperature etc) diverges and leaves behind unreasonable results
which are of little use. In many such cases, it helps to automatically...
FLUENT 6.1 - How to report the standard deviation, average, min and max of a quantity on a list of surfaces through TUI commands
|FLUENT users want to be able to obtain the reports of standard deviation, average value, minimum and maximum value of a field variable on a list of surfaces, using only TUI commands, in a batch...|
Best practices for using segregated solver with compressible flow
|In the AER team's experience, the following works well for compressible flows when using the segregated solver:
1) Initialize the flow to be near stagnation (velocity smal but not zero,...
How to change discretization schemes using TUI?
|How to change discretization schemes using TUI?
Use the following text commands as appropriate followed by the appropriate number from the list...
Contours display produces contour plot of other quantity than has been selected
|Mixsim 2: Post-processing trouble in MixSim AND when switching to FLUENT, and in FLUENT 6 stand-alone when re-reading in the case and data file:
I set-up a vessel with a Klopperboden bottom,...
Adjusting mass flow-inlet boundary to achieve a target thrust
|For external aero applications involving the modeling of a full aircraft with
engine and pylon, client typically knows the massflow rate incoming to the
engine fan inlet and also the thrust...
Tackling High pressure flow simulation in Fluent
|Experience divergence when solving a high pressure choked flow
The procedure for tackling this type of high pressure flow is simple but not always intuitive. Here are the strategies that be used...
Model Forced Diffusion in binary gas or liquid mixtures (single phase only).
Model forced diffusion in binary mixtures (single phase) mixtures.
J = J_ordinary + J_forced
J1_ordinary = -rho D12 Grad yi
J1_forced = -rho^2 * w1 * w2 * y1 * y2 * D12 * (F1...
The operating pressure is stored in both case and data files
|Let's setup a problem ("case1.cas", "case1.dat") with a certain operating pressure Pop1.
Modify "case1.cas" by changing thse operating pressure to Pop2 and any other variables then save...
To create transient Ensight case and data files from data files which were saved at discrete time steps.
|In FLUENT 6.0.20, transient Ensight case and data files cannot be exported.
If there are case and data files saved at discrete time steps in FL6.0.20, these data files
can be used to generate...
UDF to compute forces and moments (torques) on surface zones and print results to file
|Currently, Fluent cannot print force/moment data to file, only to screen.
* UDF and SCHEME interface have been added to compute surface forces/moments and print results to file...
Selection of surface-type through TUI
|Selection of surface type through TUI is very useful especially in cases where there are hundreds of point-surfaces or plane-surfaces.
Following three scheme files would allow an user to select...
Extract pressure and velocity magnitude from point data from input file
|Given set of point data (x,y,z), extract the pressure or velocity magnitudes and print them to file.
A UDF was created for this purpose. Contact ww to obtain the files and an example.
Here is the...
Entire fan udf in c program
|The user defined fan udf has a part of the code in fortran77 and the remaining part in c language.The entire code has been changed into c language.
Following are the steps to be followed:
How to specify velocity-inlet to interior faces types.
|There are cases where user wants to specify velocity-inlet to internal zones. For example, lets say we have a cylinder completely inside the a box. Lets assume that inside of the cylinder is...|
In the energy equation, when Viscous heating is turned on, Pressure work must also be turned on.
|Consider flow through a capillary ID 1 mm, Length 20 mm, adiabatic wall and inlet velocity 0.02 m/s, 300 K
Fluid: m = 0.8 Pa.s, r = 600 kg/m3, k = 0.1 W/(mK), Cp = 2600 J/(kgK)
Therefore, Re =...
Fan pressure drop as a function of radius
|Compute fan pressure drop as a function of radial distance from the center of rotation of the fan (and flow kinetic energy).
This solution consists of the following files:
* jump.c = UDF to...