A SENSITIVITY BASED OPTIMIZATION APPROACH FOR AEROACOUSTIC PROBLEMS

This paper proposes an approach for the sensitivity computation of an aeroacoustic problem via the solution of the continuous sensitivity equations. The equations are derived by differentiating the coupled system (Navier-Stokes equations and the linearized Euler equations) with respect to design parameters. The obtained acoustic sensitivity information can be used to analyze the flow control variable’s influence on the acoustic field or to calculate the gradient of an objective functional within aeroacoustic optimization problems. The components of the coupled sensitivity solver are systematically verified

NUMERICAL SIMULATION OF ACOUSTICS IN HETEROGENEOUS MEDIA

Noise influenced by multiphase flows becomes an increasingly important issue. Numerical simulations can help for a better understanding of sound behavior within heterogeneous media. In this work, we present a coupled approach for computing incompressible heterogeneous fluids with sound wave propagation. The linearized Eulerian equations are used for the transport of the sound waves. We investigate the propagation of the waves in the presence of a fluid/fluid interface and we verify the introduced approach. The method is also tested with an inclined interface, where different refraction angles are investigated. The refraction as well as the reflection of sound waves can be predicted with errors of less than one percent

Extrapolation methods for accelerating unsteady partitioned fluid-structure interaction simulations

The advantages of an unsteady implicit partitioned Fluid-Structure Interaction Scheme are; especially for large time step sizes; accompanied by a high number of inner iterations needed. This work investigates the use of extrapolation techniques in between time steps to obtain a smaller number of inner iterations. In contrast to previous works not only the structural displacement but also the fluid field variables are considered for extrapolation. The different extrapolation approaches are compared within a numerical benchmark