The present work investigates sidewall effects on the characteristics of three-dimensional (3-D) compressible flows over a rectangular cavity with aspect ratios of L/D = 6 and W/D = 2 at Re D = 10 4 using large-eddy simulations. For the spanwise-periodic cavity flow, large pressure fluctuations are present in the shear layer and on the cavity aft wall due to spanwise vortex roll-ups and flow impingement. For the finite-span cavity with sidewalls, pressure fluctuations are reduced due to interference to the vortex roll-ups from the sidewalls. Flow oscillations are also reduced by increasing the Mach number from 0.6 to 1.4. Furthermore, secondary flow inside the cavity enhances kinetic energy transport in the spanwise direction. Moreover, 3-D slotted jets are placed along the cavity leading edge with the objective of reducing flow oscillations. Steady blowing into the boundary layer is considered with momentum coefficient Cμ = 0.0584 and 0.0194 for M∞ = 0.6 and 1.4 cases, respectively. The three-dimensionality introduced to the flow by the jets inhibits large coherent roll-ups of the spanwise vortices in the shear layer, yielding 9-40% reductions in root mean square (rms) pressure and rms velocity for both spanwise-periodic and finite-span cavities.
|Original language||English (US)|
|Number of pages||14|
|State||Published - 2019|
Bibliographical noteFunding Information:
We thank Yang Zhang for the insightful discussions on cavity flow experiments. This material is based upon work supported by the U.S. Air Force Office of Scientific Research under award numbers FA9550-13-1-0091 and FA9550-17-1-0380 (Douglas Smith, Program Manager). Y. Sun, Q. Liu, and K. Taira thank the computational support offered by the Research Computing Center at Florida State University.