Large Eddy Simulation of Mixing in a Round Jet in Cross-Flow

Abstract

With the final objective of optimizing the “Micromixing” combustion principle with means of the commercial CFD code STAR-CD, Large Eddy Simulation (LES) is used to study passive scalar transport and mixing in a round jet in a laminar cross-flow. Simulations were performed at a jet to cross-flow momentum ratio of 5.7, and a Reynolds number of 5000 based on the jet velocity and jet exit diameter. An attempt is made to provide a criterion for optimal structured meshing for Jets in Cross-flow (JICF). The performance of a structured grid based on the Taylor microscales is investigated and has been found successful. Mean and turbulent statistics are compared to data from the experiments by Su & Mungal (2004) and to Direct Numerical Simulation (DNS) performed by Muppidi & Mahesh (2006-2007). The mean scalar field from the simulation shows a very good agreement with the experimental and the DNS results. The fluctuating field terms show some differences. Given the uncertainties in the experimental configuration, overall, the agreement is quite reasonable. This study confirms the ability of the commercial CFD code STAR-CD to reproduce complex flow phenomenon. More generally, the simulation rational will form the baseline for future “Micromixing” combustion simulations.