NAFEMS Hybrid RANS-LES for Industry Seminar 2015

For many companies there is a growing desire to improve the accuracy of their CFD simulations, in order to improve correlation to experiments and to allow more of their design to be undertaken in Computational Fluid Dynamics.This desire for greater accuracy has led many to look at Large Eddy Simulation (LES). Whilst LES models can in general provide a much better alternative to RANS models for unsteady flows, they do so at a much higher cost, so much higher that for high-Reynolds numbers flow these costs are too great for general purpose calculations. Hybrid RANS-LES methods offer an attractive alternative, where RANS methods are applied in regions of the flow which are easy to predict (attached, steady flow) and Large Eddy Simulation methods in the more challenging separated regions. These methods, if correctly applied, can provide close to LES accuracy for a greatly reduced computational cost.This seminar focused on these hybrid RANS-LES methods and in particular what improvements they offer over pure RANS and LES approaches. Through several presentations from experts representing some of the key engineering sectors (automotive, aerospace & turbo-machinery), practical examples of these methods were presented, offering attendees a chance to understand and question if these methods could be applied to their simulations.In addition to more applied talks, there were several talks from globally recognized experts on hybrid RANS-LES methods, who talked of the latest developments and gave concrete examples of where hybrid RANS-LES has brought about improvements.The major CFD code vendors were also represented at the seminar, allowing attendees to see the full range of options open to their company or institution.