Establishing New Models of Subconvective Wall Pressure and Shear-Stress Fluctuations in Non-Equilibrium Boundary Layers at High Reynolds Number
Abstract
This proposal describes a 5-year research effort to establish new more accurate models for low-wavenumber subconvective turbulent wall pressure and shear-stress fluctuations produced by high-Reynolds number turbulent boundary layers in strongly non-equilibrium and inhomogeneous flow environments of particular Naval relevance. This work is the natural extension of our current effort (concluding in 2025) into subconvective pressure fluctuations in homogeneous boundary layers with mild pressure gradients. That work has brought a revolutionary new approach to low-wavenumber pressure measurement using sub-resonant sensors that has enabled, for the first time, measurements of the complete subconvective wavenumber frequency spectrum. At the same time, we developed new approaches to optical flow measurement that allow for simultaneous measurement of the wall pressure and associated turbulence structures on the very large scales that define the lowest wavenumber portions of the spectrum. In the work described here we will attempt to add unsteady shear-stress measurement to this suite of groundbreaking experimental methods. As with all VT research efforts, the work plan includesat a fundamental level the participation of undergraduates and graduate students in the research with the goal of building broad STEM awareness and research training in areas of critical interest to the Navy. Furthermore, we see this effort as part of a larger ongoing collaboration with Navy personnel (in particular, Jason Anderson s team at NSWCCD). Technically speaking, the effort will takea systematic approach to adding the complexities of inhomogeneity and non-equilibrium behavior, beginning with simple and relevant configurations such as two and three-dimensional steps and gaps, and progressing to technically more challenging issues as three-dimensional boundary layer skewing, vortex roll-up, separation, and lateral curvature. Configurations for these more complex flow effects will be fully defined as part of the research, but previously well-studied wing-body junction, body of revolution, and bump configurations appear to be credible candidates.APPROVED FOR PUBLIC RELEASE
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 15, 2024
- Source ID
- N000142412344
Entities
People
- William J. Devenport
Organizations
- Office of Naval Research
- United States Navy
- Virginia Tech