Radiative and dispersive behavior of instabilities in a highly-cooled hypersonic boundary layer
Abstract
This work is concerned with investigating the newly discovered phenomena of dispersion and acoustic radiation from second-mode instabilities in highly-cooled hypersonic boundary layers; and characterizing instability growth and breakdown over a range of wall temperature ratios inaccessible by conventional hypersonic wind tunnels.The primary technical objective is to develop and refine novel non-intrusive diagnostictechniques for instability and transition measurements in short-duration, high-enthalpyfacilities for use in this and other high-speed, flow-physics studies.With the proposed work, we aim to answer the following key scientific questions:• Can the dispersive behavior and spontaneous emission of sound observed in numerical simulations of highly cooled hypersonic boundary layers be reproduced experimentally?• What effect does this acoustic radiation and dispersion have on the growth rate of instabilities in highly-cooled hypersonic boundary layers?• Could the this phenomena be part of a multi-mechanism boundary-layer transition control strategy?• What is the effect of wall cooling ( Tw/Te ? 0.5 ? 1.1 ) on the strength of the dispersion and pressure field emanated from the wave packets relative to the disturbance strength, as well as on the wave-packet structure?• How does a nonzero incidence angle and/or the presence of an entropy layer affect the radiation phenomenon?The secondary technical objective of the proposed work is to assess the HYPULSEhypersonic facility as a long-term, R&D hypersonics facility.The approach to achieve these objectives will be an experimental research effort (Parziale and Laurence - FLDI and schlieren) to be performed in the HYPULSE hypersonic facility (Orbital-ATK with Inoveering consulting - facility operation), guided in years 2 and 3 by computations (Bitter - LST and DNS).
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 28, 2018
- Source ID
- FA95501810403
Entities
People
- Nicholaus J. Parziale
Organizations
- Air Force Office of Scientific Research
- Stevens Institute of Technology
- United States Air Force