Author: Stanley Mack Publisher: ISBN: Category : Languages : en Pages : 74
Book Description
Similarity-law analysis is applied to the case of flow noise due to a cavity resonator. Data is generated using generalized cavity models which are activated by a small wind tunnel. Analysis of the graphical display of non-dimensional parameters reveals regularities which indicate the nature of mechanism. Further investigation of the driving force involves use of hot wire anemometry and digital computer storage, analysis and display. (Author).
Author: Paul J. Zoccola, Jr. Publisher: ISBN: 9781423536567 Category : Languages : en Pages : 180
Book Description
The resonant excitation of a cavity by an equilibrium turbulent grazing flow was investigated. The objectives of the research were first, to understand the dynamic processes related to the shear tones generated by vortex shedding from the upstream edge, and then to determine practical techniques for controlling the excitation and reducing the resonance. Detailed measurements of the cavity pressure and the velocity field in the opening were performed. Spectral data on cavity pressure fluctuations were analyzed over a range of speeds to determine the behavior of both the shear tones and cavity tones during non-resonant and resonant conditions. The cross-spectral properties between the velocity components and cavity pressure were also obtained. The data support the finding that the resonant and nonresonant conditions are distinguished by the behavior of the convection velocity and by the distribution of energy production in the flow field. Techniques for controlling cavity resonance were also investigated. The measurements and data analyses techniques discussed above were also performed for three practical devices. These include a technique, developed by the author, whereby fluid is diverted into the cavity from the boundary layer. The diversion technique is the most effective in reducing cavity resonance.
Author: Publisher: ISBN: Category : Languages : en Pages : 180
Book Description
The resonant excitation of a cavity by an equilibrium turbulent grazing flow was investigated. The objectives of the research were first, to understand the dynamic processes related to the shear tones generated by vortex shedding from the upstream edge, and then to determine practical techniques for controlling the excitation and reducing the resonance. Detailed measurements of the cavity pressure and the velocity field in the opening were performed. Spectral data on cavity pressure fluctuations were analyzed over a range of speeds to determine the behavior of both the shear tones and cavity tones during non-resonant and resonant conditions. The cross-spectral properties between the velocity components and cavity pressure were also obtained. The data support the finding that the resonant and nonresonant conditions are distinguished by the behavior of the convection velocity and by the distribution of energy production in the flow field. Techniques for controlling cavity resonance were also investigated. The measurements and data analyses techniques discussed above were also performed for three practical devices. These include a technique, developed by the author, whereby fluid is diverted into the cavity from the boundary layer. The diversion technique is the most effective in reducing cavity resonance.
Author: M. C. Harrington Publisher: ISBN: Category : Languages : en Pages : 10
Book Description
Investigations of the excitation of cavity resonance by air flow were extended. Oscillations induced by flow across the mouth of box shaped cavities, with and without lips, were studied in water and air. This device consists of a box with a flexible side upon which a sinusodial variation in volume of the box is imposed, thus inducing velocities normal to the flow in the mouth of the box. Motion pictures of dye, injected upstream of the mouth, indicate that vortex formations are caused by the fluctuating velocity fields normal and tangential to the mouth. This vortex formation causes the turbulent mixing zone, containing free stream kinetic energy, to curve into and out of the box. The instability of the mixing zone causes alternating pressures in the box, which in turn may provide the excitation mechanism for resonance. Flexibility of the structure in water, and the compressibility of air, provide energy storage between cycles. In either case the amplitude of the peak-to-peak pressure changes determine the magnitude of the velocity variations normal to the flow in the mouth of the box. (Author).
Author: Stanley Mack
Author: Paul Zoccola (Jr., J.)
Author: Paul J. Zoccola, Jr.
Author: 
Author: 
Author: Michael A. Kegerise
Author: M. C. Harrington
Author: L. Mongeau
Author: Louis Cattafesta
Author: Jake Izikson