COMPUTATIONAL ANALYSIS OF FLOW-NOISE SOURCES IN BOUNDARY LAYERS WITH SURFACE-MOUNTED OBSTACLES
Abstract
We propose to perform a computational study of high-Reynolds-number, nonequilibrium turbulent boundary-layer flows over surface-mounted obstacles to predict their acoustic and unsteady wall-pressure signatures and elucidate the flow-noise generation mechanisms. Special attention will be paid to the subconvective wavenumber spectra of the fluctuating wall pressure and their downstream development, which are particularly detrimental in terms of exciting structural vibrations and acoustic radiation. Large-eddy simulation will beemployed to compute the turbulent flow field, and acoustic radiation will be computed based on the Lighthill equation solved using a boundary-element method. Improved methods for accurate and cost-effective flow-noise computations, including the use of a wall model in LES, will be explored and first evaluated in simpler flows including a canonical equilibrium boundary layer and boundary-layer flow over a two-dimensional forward-facing step. Maininvestigations will involve three-dimensional surface obstacles of various shapes and sizes in isolation, pairs and clusters. Working closely with the Virginia Tech experimental group, we will perform computations to assist in the experimental design, provide mutual validations of computational and experimental results, and complement experimental measurementswith quantities that may be difficult to measure. Computational results will be used to identify dominant flow-noise sources and source regions, and provide data and physical insight into noise-source modeling.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 31, 2020
- Source ID
- N000142012687
Entities
People
- Meng Wang
Organizations
- Office of Naval Research
- United States Navy
- University of Notre Dame