Detailed Experimental Characterization of Flow-Surface Interactions and Dipole Noise Sources at the Interface Between Compliant Surfaces and Turbulent Boundary Layers
Abstract
This proposal substantially expands our effort to characterize experimentally flow-structureinteractions and generation of dipole noise at the interface between a compliant wall and highReynolds number turbulent boundary layers. The experiments will beperformed in a recently constructed water tunnel extension to the JHU optically index matchedfacility at higher speeds than before. Matching the flow velocity with the shear speed of thecompliant wall will be used to stimulate non-linear flow-structure interactions by generating walldeformations large enough to alter the flow. Two series of experiments are proposed: (i) a largeflat surface, and (ii) surfaces containing two dimensional upstream and downstream facing stepsas well as cavities aimed to characterize steps slits and gaps in the compliant coating. Dataanalysis involving conditional sampling, spatial and temporal correlations and other statisticaltools will focus on characterizing key mechanisms affecting the coupling between forcesgenerated by the flow, shape of the elastic surface, and the radiated nose. On-going analysisbased on prior data shows strong impact of both the pressure field and the wall-normal velocityfluctuations on the deformation at frequencies corresponding to turbulent structures in the logregion of the boundary layer. The results for both experimental settings will be compared topredictions of theoretical and computational models for the flow-structure interactions, and fordipole noise sources generated by rough wall boundary layers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 08, 2016
- Source ID
- N000141612300
Entities
People
- Joseph Katz
Organizations
- Johns Hopkins University
- Office of Naval Research
- United States Navy