Absolute Instability of Interacting Planar Mixing Layers and Wakes

Abstract

A joint experimental and computational (stability) investigation of the interaction between planar mixing layers and wakes is proposed. Particle image velocimetry (PIV) will be deployed for the planar shear layer/wake configuration in the facility used by Tian et al. (2012), using an existing fastframe rate PIV system. Two-dimensional, two-component (2D/2C) velocity fields will be obtained downstream of the trailing edge of a flat plate with variable thickness, and the flow speed (effective Reynolds numbers for each incoming boundary layer) will be varied. Sampling frequencies and durations will be designed to obtain spatially resolved and temporally converged mean velocity fields for input to the analysis, and to permit definitive identification of the spectral signatures of the various stability phenomena for comparison with the computational results. The test matrix is designed to permit transiting the region of absolute instability by varying the momentum thicknesses of the interacting shear layers at a constant velocity ratio around 0.5.

Document Details

Document Type
DoD Grant Award
Publication Date
Jan 21, 2022
Source ID
FA95502110052XX0

Entities

People

  • Beverley McKeon

Organizations

  • Air Force Office of Scientific Research
  • California Institute of Technology
  • United States Air Force

Tags

Fields of Study

  • Physics

Readers

  • Fluid Mechanics and Fluid Dynamics.