Isogeometric Analysis of Hydrodynamic Noise Generation

John Evans, University of Texas

Flow over a flexible structure is known to produce sound as well as vibrations in the structure. Modeling these acoustic fluctuations and structural vibrations is important for a variety of engineering applications. For example, a key aspect of submarine design is to minimize sound production due to turbulent flow over its hull, sail, rudder, stern planes, and propellers. Similarly, noise reduction is an important aspect in the design and optimization of windmill turbines.

We consider numerical modeling of structural-acoustic noise generated by fluid-structure interaction utilizing non-uniform rational B-spline (NURBS)-based isogeometric analysis. Our model involves the numerical solution of a fluid problem about a rigid body followed by the simulation of a time-dependent structural-acoustic problem driven by the flow field. Stabilized and multiscale space-time finite element formulations are presented for both the nonlinear fluid and linear structural-acoustic problems. A key aspect of this work is a multiscale decomposition of the Lighthill stress tensor appearing in the structural-acoustic problem. Numerical results illustrate the accuracy and feasibility of our methodology.

Abstract Author(s): John A. Evans, Thomas J.R. Hughes