Large Eddy Simulations of Hot Supersonic Jets for Aeroacoustics

The technical objective of this proposal is to develop and demonstrate LES capability to predict hot jet noise at supersonic operating conditions of tactical aircrafts. We also propose an LES based non-linear instability method (NPSE) to provide reduced order, physics-based models for noise generated by large-scale turbulent structures in hot jets. CASCADE’s unstructured solver, CHARLES, will be used for LES noise prediction. To achieve this, fully compressible N-S equation with dynamic SGS model will be solved in the near field, this data is then used to calculate the far field noise using acoustics projection methods. Near-field LES results will also provide mean flow fields and amplitude of instability waves required for NPSE modeling. Careful validation of the flow field and noise predictions will be conducted in close partnership with an industry partner (UTRC). In phase I, the feasibility of proposed methods will be demonstrated using pressure-matched hot jets with round nozzles. In phase I option, we extend the complexity to chevron nozzles and pressure-mismatched operating conditions. In Phase II, we focus on realistic nozzle geometries and engine configurations. In addition, the effect of airframe will be integrated in noise calculations.