Receptivity to Breakdown Mechanisms During Transition on Hypersonic Forebodies
Abstract
We propose to examine the mechanisms associated with hypersonic transition on two canonical forebodies, specifically the cone and the ogive. The features of the basic states in these configurations differ crucially from those of a flat plate with respect to streamline curvature, pressure gradients and changing edge conditions. The simulation pyramid will employ advanced stability techniquesto first extract principal properties of each basic state, which will then inform high-fidelity 2D and 3D DNS. The flow parameters are chosen to be representative of current interest, and for which supporting data is available for validation. The obtained fluctuations will be analyzed over the entire process of transition, including receptivity, stability, linear growth, saturation, non-linear dynamics, breakdown and subsequent establishment of turbulence. Receptivity pathways using different types of forcing, wall temperature and nose bluntness will be explored on a subset of cases chosen carefully to optimize computational resources. Crossflow instabilities will be delineated by considering angle of attack with azimuthally periodic and compact roughness elements, respectively. The desired insight will be facilitated by recently developed concurrent and post-processing techniques which can identify causality in thermo-acoustic-vortical dynamics even into the breakdown regime, modal techniques that account for intermittency and transient growth, and traditional techniques such as bicoherence. These will be deployed to examine the development of modal instabilities,including trapped components, spectral broadening and quadratic-phase coupling, multi-modal and non-modal interactions, three-dimensional thermal-acoustic-vortical energy balance, coherent structure evolution and correspondence with loads associated with skin friction and heat transfer. In addition to yielding fundamental new inferential insight into forebody transition phenomena, the techniques used will be applicable to other configurations and aid in identifying potential approaches to interfere in perturbation growth.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2021
- Source ID
- N000142112408
Entities
People
- Datta V. Gaitonde
Organizations
- Office of Naval Research
- Ohio State University
- United States Navy