Large Eddy Simulation of a Low Speed Subsonic Jet: A Validation Study

Abstract Low-speed subsonic jets are commonly encountered in many flow systems such as in chimney exhausts, impinging jets, inlets in combustors of diesel engines and gas turbines. Large-eddy simulation of a Mach 0.1, three-dimensional plane (square) turbulent air jet was performed. The Reynolds number of the jet based on the jet width was 3 × 104. The width of the jet was 0.013 m. The aim of the present work was to develop a three-dimensional compressible parallel LES finite-volume code and validate it against an experimental free jet test case. A robust novel numerical scheme based on the blending of Riemann invariants and the exact Godunov solver, capable of handling low Mach number flows without preconditioning, was used. The Smagorinsky sub-grid scale model was used to model the unresolved stresses. An investigation was carried out into the self similarity behavior of the jet and the two-point correlations and the dissipation was computed. It is observed that istropicity of turbulence only exists in the v and w components and self-similar behavior was observed approximately beyond 90 jet widths downstream.