HIGH REYNOLDS NUMBER QUIET MACH 6 SWEPT-FIN CONE EXPERIMENTS: FLOW INSTABILITIES AND TRANSITION CONTROL

Abstract

A three-year program is proposed that is designed to document flow instabilities leading to turbulent transition on a swept-fin cone model. The initial model will consist of a 7~ half-angle sharp-tipped right-circular cone on which is placed a fin with a 70~ sweep angle. The same geometry has been examined experimentally in the Purdue University BAM6QT, and in a direct numerical simulation by Knutson et al.[12]. The model in the proposed experiments will be 3-times larger than in the previous studies, with a length of 1.219 m (48.2 in.), that will completely reside in the 3.6 m long quiet test rhombus of the new University of Notre Dame Quiet Mach 6 Wind Tunnel.This will provide unparalleled spatial resolution for detailed measurements, and at the nominal unit Reynolds number of 11~106m~1, result in turbulent transition on the model that is not possible at the smaller scale. Infrared thermography will be used to quantify heat flux and subsequently the transition front. Detailed measurements will be performed through a combination of surface-mounted pressure sensors, and off-wall spatial surveys utilizing a fastresponse pressure probe mounted on a 3-D traversing mechanism. DNS simulations[12] for the swept-fin cone geometry have indicated strong cross-stream pressure gradients near the fin and cone wall that is expected to lead to cross-flow instability with stationary cross-flow modes being the dominant mechanism of transition. The experiments will investigate cross-flow instability and transition control in these regions using discrete roughness that has been successful on cones at angles of attack at Mach 3.5 and 6[20, 15, 3].

Document Details

Document Type
DoD Grant Award
Publication Date
Apr 25, 2019
Source ID
N000141912230

Entities

People

  • Thomas Corke

Organizations

  • Office of Naval Research
  • United States Navy
  • University of Notre Dame

Tags

Fields of Study

  • Physics

Readers

  • Fluid Dynamics.
  • Fluid Mechanics and Fluid Dynamics.