Another Look at Supersonic Cavity Flows and Their Control

A Mach 2 supersonic cavity flow, with L/D between 1 and 5, was investigated with velocity field measurements, acoustic/unsteady pressure measurements and flow visualization. The evolution in the flowfield between deep (L/D=1) and relatively shallow (L/D~5) was examined both in terms of mean and unsteady L/D flow properties. By implementing microjet-based actuators, the flow induced resonance and the accompanying high unsteady pressure loads inside the cavity are significantly reduced, both in terms of the overall sound pressure level (OASPL) and the dominant cavity tone. The required mass flux of the microjet actuator is very low, depends on the L/D: Bc between 0.1% to 0.5% is sufficient for 5 to 11 dB reduction in OASPL and 13 to 28 dB on dominant cavity tones.

[1]  Dimitri Papamoschou,et al.  Visual observations of supersonic transverse jets , 1993 .

[2]  D. S. Dolling,et al.  Suppression of Pressure Oscillations in High-Mach-Number, Turbulent, Cavity Flow , 2001 .

[3]  Aldo Rona,et al.  AN OBSERVATION OF PRESSURE WAVES AROUND A SHALLOW CAVITY , 1998 .

[4]  Anuradha M. Annaswamy,et al.  Aeroacoustic Properties of Supersonic Cavity Flows and Their Control , 2003 .

[5]  Rodney Clark,et al.  F-111 generic weapons bay acoustic environment , 1988 .

[6]  A. Vakili,et al.  Control of Cavity Flow by Upstream Mass-Injection , 1994 .

[7]  R. L. Sarno,et al.  Suppression of flow-induced pressure oscillations in cavities , 1994 .

[8]  Anuradha M. Annaswamy,et al.  High-Frequency Excitation Active Flow Control for High-Speed Weapon Release (HIFEX) , 2004 .

[9]  Hanno H. Heller,et al.  Aerodynamically Induced Pressure Oscillations in Cavities - Physical Mechanisms and Suppression Concepts , 1975 .

[10]  K. Krishnamurty,et al.  Acoustic radiation from two-dimensional rectangular cutouts in aerodynamic surfaces , 1955 .

[11]  Leonard Shaw,et al.  High speed application of active flow control for cavity acoustics , 2000 .

[12]  R E Dix,et al.  Engineering Model of Unsteady Flow in a Cavity , 1991 .

[13]  Noel T. Clemens,et al.  Experimental Study of Shear-Layer/Acoustics Coupling in Mach 5 Cavity Flow , 2001 .

[14]  E. Covert,et al.  Flow-Induced Pressure Oscillations in Shallow Cavities , 1971 .

[15]  A. Roshko.  Some Measurements of Flow in a Rectangular Cutout , 1955 .