Influence of Different Subgrid Scale Models in LES of Supersonic Jet Flows

TL;DR

This study investigates how different subgrid scale models affect large eddy simulations of supersonic jet flows, aiming to improve aeroacoustic analysis of rocket plumes.

Contribution

It develops an in-house LES tool and compares classical, dynamic Smagorinsky, and Vreman models for simulating compressible jet flows.

Findings

Different subgrid models influence jet mixing predictions.

The LES tool accurately reproduces high-fidelity jet flow results.

Comparison highlights strengths and limitations of each model.

Abstract

Current design constraints have encouraged the studies of aeroacoustics fields around compressible jet flows. The present work addresses the numerical study of subgrid scale modeling for unsteady turbulent jet flows as a preliminary step for future aeroacoustic analyses of main engine rocket plumes. An in-house large eddy simulation (LES) tool is developed in order to reproduce high fidelity results of compressible jet flows. In the present study, perfectly expanded jets are considered because the authors want to emphasize the effects of the jet mixing phenomena. The large eddy simulation formulation is written using the finite difference approach, with an explicit time integration and using a second order spatial discretization. The energy equation is carefully discretized in order to model the energy equation of the filtered Navier-Stokes formulation. The classical Smagorinsky model, the dynamic Smagorinsky model and the Vreman models are the chosen subgrid scale closures for the present work. Numerical simulations of perfectly expanded jets are performed and compared with the literature in order to validate and compare the performance of each subgrid closure in the solver.