Large-Eddy Simulation of a Turbulent Compressible Round Jet

Abstract

A large-eddy simulation (LES) of a high-Reynolds-number jet was performed. A numerical scheme that is uniformly fourth-order accurate in time and space was used to solve the Favre-e ltered Navier ‐Stokes equations. The subgrid-scale stresses were computed using a compressible form of Smagorinsky’ s model. A cold Mach 1.4 nozzlewithaReynoldsnumberof1 :2 ££ 106 wassimulated.Incontrasttosimilarstudies,theentirenozzlegeometry including the nozzle lip was modeled. The LES simulation accurately captures the physics of the turbulent e ow. The agreement with experimental data is relatively good and improves on results in the current literature. This improvement can be attributed to the numerical scheme and the modeling of the nozzle. In addition, a twopoint correlation technique was used to quantify the turbulent structures in the jet mixing layer and showed that computational techniques can be used to characterize such structures for application to Lighthill’ s acoustic analogy. Two-point space correlations were used to obtain a measure of the integral length scale, which proved to be approximately 1 Dj. Two-point space-time correlations were used to estimate the convection velocity for the turbulent structures. This velocity estimates ranged from 0.57 to 0.71 Uj and is in agreement with theory.