Hypersonic Boundary Layer Turbulence (BOLT II) Flight Test Experiment
Abstract
Predicting thermal loading is one of the most serious and challenging problems encountered by hypersonic vehicle designers. The basic research objective of this proposal is improved understanding and prediction of the heat flux and skin friction associated with naturally occurring and strained hypersonic boundary layer turbulence (BOLT II) during flight. The testbed for the study will be derived from the AFOSR boundary layer transition (BOLT) configuration, which creates a complex flow path with pressure gradients and stationary vortex streaks, which leads to competing transition mechanisms and finally a complex turbulent flow. The present project has four goals: • Goal 1 – Add to the national database by quantifying the turbulent heat flux and skin friction on the BOLT II configuration during a hypersonic flight test with natural transition. These data fill a void in the hypersonic database, which, for example, will then reduce uncertainty in (1) understanding the initial structure of turbulence in the presence of secondary flow and instability vortices and (2) knowing if and when local similarity begins under these conditions. A flight test is preferred, as natural transition within quiet tunnels has proven difficult and the wall temperature ratios are mismatched. • Goal 2 – Characterize the complex turbulent flow structure and turbulent transport processes using state of the art scientific ground test (quiet tunnel and flight duplication) and numerical simulation methods (linear and nonlinear stability and LES-RANS), while also assessing the ability of these tools to predict turbulent thermal loading during flight. • Goal 3 – Advance a new turbulent heat flux theoretical treatment for strained, non adiabatic flow on the BOLT II configuration. The focus is accounting for how secondary flow, strain rates, and stability driven vortex flow patterns alter the near wall turbulence dynamical structure and thermal transport.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 14, 2022
- Source ID
- FA95501910154
Entities
People
- Rodney D W Bowersox
Organizations
- Air Force Office of Scientific Research
- Texas Engineering Experiment Station
- United States Air Force