I would like to solve a user scalar transport equation in ANSYS CFD with advection and zero diffusion. When I set diffusion to zero, there is an error. How can I eliminate diffusion and still solve my transport equation with the flow?
January 25, 2023 at 7:16 amFAQParticipant
The treatment of quantities that are exactly zero is subject to the math processor of the machine, if a divide by zero is encountered. Warnings are issued to prevent this, or indicate that it is occurring. Diffusion (even with significantly non-zero coefficients) is a very slow process, so the effects of a low diffusivity on the scalar streamlines will be negligible (unless the residence time is huge). The best practice (to avoid the pitfalls of divide-by-zero calculations), is to set the diffusivity to something just above machine round-off, (ie: 1.0e-15), and solve with double precision.
Introducing Ansys Electronics Desktop on Ansys Cloud
The Watch & Learn video article provides an overview of cloud computing from Electronics Desktop and details the product licenses and subscriptions to ANSYS Cloud Service that are...
How to Create a Reflector for a Center High-Mounted Stop Lamp (CHMSL)
This video article demonstrates how to create a reflector for a center high-mounted stop lamp. Optical Part design in Ansys SPEOS enables the design and validation of multiple...
Introducing the GEKO Turbulence Model in Ansys Fluent
The GEKO (GEneralized K-Omega) turbulence model offers a flexible, robust, general-purpose approach to RANS turbulence modeling. Introducing 2 videos: Part 1 provides background information on the model and a...
Postprocessing on Ansys EnSight
This video demonstrates exporting data from Fluent in EnSight Case Gold format, and it reviews the basic postprocessing capabilities of EnSight.
- ANSYS Fluent: Introduction to the GEKO Turbulence Model Part I
- Delete or Deactivate Zone in Fluent
- ANSYS Polyflow: Adaptive Meshing Based on Contact
- Aero-Mechanical Simulation of Turbomachinery Blading
- What is meant by Warning: Flow boundary zone 18 is adjacent to a solid zone?
- Apply Custom Material Properties in Fluent
- ANSYS System Coupling: Two Way Fluid Structure Interaction – Part 1
- Predict Gearbox Lubrication, Oil Temperature and Churning Losses using CFD Simulation
- Check CPU Time in ANSYS FLUENT
- How to Predict Performance of Bioreactors and Mixing Tanks