Velocity Fluctuation Algorithm Large Eddy Simulation

- April 28, 2023 at 8:11 pm
  
  Ibrahim El-Gheriani
  Subscriber
  
  Hello everyone,
  I have a question regarding the significance of the velocity fluctuation algorithm for the inlet boundary in LES. Recently, I started an LES simulation and just noticed that I inadvertently left the default option, "No Perturbations," instead of selecting the recommended "Vortex Method." Unfortunately, I cannot restart the simulation due to an approaching project deadline, and LES simulations require considerable time to complete.
  Can anyone advise on the potential implications of this oversight on my simulation results? For context, I have implemented a User-Defined Function (UDF) for the velocity profile and used a precursor Unsteady Reynolds-Averaged Navier-Stokes (URANS) simulation as a starting point for my LES.
  Any insights or suggestions would be greatly appreciated. Thank you in advance!
- May 3, 2023 at 5:45 pm
  
  Federico Alzamora Previtali
  Subscriber
  
  "No perturbations" would be suitable if the level of turbulence at your inlet is negligible compared to the rest of the flow. In this case, the velocity fluctuations at the inlet are neglected, creating a "flat" turbulent profile.
  LES models require realistic inlet conditions. If the turbulence at your inlet is important, I imagine this would impact your solution.

Viewing 1 reply thread

You must be logged in to reply to this topic.

Ansys Innovation Space

Boost Ansys Fluent Simulations with AWS

Computational Fluid Dynamics (CFD) helps engineers design products in which the flow of fluid components is a significant challenge. These different use cases often require large complex models to solve on a traditional workstation. Click here to join this event to learn how to leverage Ansys Fluids on the cloud, thanks to Ansys Gateway powered by AWS.

Earth Rescue – An Ansys Online Series

The climate crisis is here. But so is the human ingenuity to fight it. Earth Rescue reveals what visionary companies are doing today to engineer radical new ideas in the fight against climate change. Click here to watch the first episode.

Ansys Blog

Subscribe to the Ansys Blog to get great new content about the power of simulation delivered right to your email on a weekly basis. With content from Ansys experts, partners and customers you will learn about product development advances, thought leadership and trends and tips to better use Ansys tools. Sign up here.

Trending discussions