Abstract
This paper presents an investigation of the flow physics and control of cavity flow oscillations using a threedimensional (3-D) array of steady jets located near the cavity leading edge. The array injects 3-D, steady flow normal to the freestreamto suppress the fluctuating surface pressure in a rectangular cavitywith a length-to-depth ratioL/Dof 6 forMach 0.3 to 0.7. Sixteen configurations are assessed for their suppression as a function of the aggregate momentum coefficient Cμ, spatial duty cycle d, and dimensionless wavelength λ/D. Significant reductions of fluctuating surface pressure are observed. Schlierenandparticle image velocimetry are performed to investigate the baselineandcontrolled flows.Companion large-eddy simulationswith spanwise periodic boundary conditions atMach 0.6 generally agreewith the experiments, despite a significant difference in theReynolds numbers.The simulations showthat control reduces the pressure fluctuations inside the entire cavity, albeit at a higher level ofCμ. Spanwisewavelike structures produced by the control input distort the shear layer, inhibit the growth of large-scale vortical structures, and reduce the strength and length scale of turbulent fluctuations near the impingement region.Aslot-configuration design guide is provided,which compares favorably with the limited available data in the literature.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 90-105 |
| Number of pages | 16 |
| Journal | AIAA journal |
| Volume | 57 |
| Issue number | 1 |
| DOIs | |
| State | Published - 2019 |
Bibliographical note
Funding Information:This material is based upon work supported by the U.S. Air Force Office of Scientific Research under awards FA9550-13-1-0091 and FA9550-17-1-0380 (program manager Douglas Smith).
Publisher Copyright:
© 2018 by the American Institute of Aeronautics and Astronautics, Inc.