Download or read book Census of India 1971 written by and published by . This book was released on 1973 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Investigation of High Subsonic Flow Over an Off Axis Longitudinal Cavity with Antiresonance Devices written by Kenneth Vaccaro (2LT, USAF.) and published by . This book was released on 1974 with total page 172 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Introductory Guide to EC Competition Law and Practice written by Valentine Korah and published by . This book was released on 1994 with total page 2354 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1976 with total page 1220 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1977 with total page 1056 pages. Available in PDF, EPUB and Kindle. Book excerpt: Sections 1-2. Keyword Index.--Section 3. Personal author index.--Section 4. Corporate author index.-- Section 5. Contract/grant number index, NTIS order/report number index 1-E.--Section 6. NTIS order/report number index F-Z.
Download or read book An Experimental Investigation of Cavity Aeroacoustics in High Speed Flows Appendix A Supersonic Data Appendix B Subsonic Data written by and published by . This book was released on 1995 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this report has been directed to study the effects of mass injection into the flow upstream of a cavity to understand the weapon bay cavity's flow field and its aeroacoustics. The objective also was to control the development of upstream boundary layer, and therefore, to control the development of the shear layer over the cavity. Control of the shear layer has enabled us to significantly reduce or to fully eliminate the weapons bay's aeroacoustic interactions. This study was performed in a wind tunnel at several nominal Mach numbers between 0.5 to 1.8 and at unit Reynolds numbers up. (AN).
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1976 with total page 1052 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Investigation of Subsonic Cavity Flows Without and with Forcing written by Jesse Clayton Little and published by . This book was released on 2005 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract: Grazing flow over a shallow cavity is characterized by a shear layer instability feedback loop that induces strong pressure fluctuations at discrete frequencies. Examples include flow over aircraft weapons bays, aircraft landing gear openings and transmission or reception optical ports on aircraft. In the first application, this behavior can result in decreased accuracy of weapons delivery, fatigue failures and lowered efficiencies. Because of the variety of unwanted effects inherent to cavity flows, their control is of interest to both military and commercial aircraft applications. The complex nature of cavity flow has been explored since the mid-20th century with accelerated study over the past 25 years in hopes of understanding and controlling major pressure fluctuations within the cavity. A key to developing a successful control scheme for this fluidic system is a detailed understanding of the physics that govern the flow-acoustic coupling mechanisms. This work provides both qualitative and quantitative measurements for use in characterizing the fluid and acoustic physics that govern the resonance phenomenon. Focus is placed on the subsonic regime with an emphasis on Mach 0.30 flow and its control. Results include the analysis of surface pressure spectra and spatial correlations, flow visualization and velocity measurement using particle image velocimetry (PIV) in various controlled and baseline (unforced) cases. These results show that a well chosen actuation scheme at or near the receptivity region of the cavity shear layer can interrupt or weaken the acoustic feedback loop and significantly reduce the sound pressure level in the cavity. Physically, this amounts to modifying the development and evolution of the coherent structures spanning the cavity and thereby changing the frequency at which these vortices impact the trailing edge of the geometry. In addition, simultaneous dynamic surface pressure and planar velocity measurements are used in low dimensional modeling for closed-loop controller design purposes. Modeling using this method allows design of accurate models from experimental results rather than relying on numerical data, which is incapable of resolving the complex nonlinear production of acoustics in the low subsonic cavity flows at this time.
Download or read book An Experimental Investigation of Cavity Aeroacoustics and Control in Subsonic Flows written by Paul Anthony Nagle and published by . This book was released on 1995 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Theoretical and Experimental Investigation of the Acoustic Response of Cavities in an Aerodynamic Flow written by H. E. Plumblee and published by . This book was released on 1962 with total page 167 pages. Available in PDF, EPUB and Kindle. Book excerpt: Theory is developed for the resonant frequencies and pressure amplifications of a rectangular cavity of arbitrary dimensions in a flow field. An intermediate step involves the derivation of radiation impedance for a cavity at all Mach numbers, using the concepts of retarded pot ntial t eory. Experim ntal results are given for small cavities tested in the subsonic regime and for cavities up to 8 in. in length at supersonic Mach numbers from 1.75 to 5 0. Comparisons are drawn between theoretical and experimental frequency and amplitude response, indicating that the theory developed gives very good definition of the problem.
Download or read book An Experimental Investigation of Cavity Aeroacoustics in High Speed Flows written by and published by . This book was released on 1995 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research presented in this report has been directed to study the effects of mass injection into the flow upstream of a cavity to understand the weapon bay cavity's flow field and its aeroacoustics. The objective also was to control the development of upstream boundary layer, and therefore, to control the development of the shear layer over the cavity. Control of the shear layer has enabled us to significantly reduce or to fully eliminate the weapons bay's aeroacoustic interactions. This study was performed in a wind tunnel at several nominal Mach numbers between 0.5 to 1.8 and at unit Reynolds numbers up to 17 millions per foot. Measurements were performed for a number of injection distributions. The large amplitude oscillations measured without mass injection was successfully and totally eliminated with proper mass injection.
Download or read book Experimental and Theoretical Study of Cavity Acoustics written by R. E. Dix and published by . This book was released on 2000 with total page 224 pages. Available in PDF, EPUB and Kindle. Book excerpt: Between 1986 and 1990, a large database was compiled at AEDC from the results of a series of wind tunnel experiments investigating the aerodynamics of flow over open cavities. The database, known as the Weapons Internal Carriage and Separation (WICS) database, covered four experiments that were completed in the AEDC wind tunnels. The initial database documentation focused on the test and data, but included very little analysis of the results. The purpose of the present work is to report analysis of the cavity acoustics and trajectory data. In addition, an updated engineering mathematical model for cavity aeroacoustics is presented.
Download or read book An Experimental Investigation of Sound Attenuation in a High subsonic Mach Number Inlet written by Michael Glen Jones and published by . This book was released on 1982 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Investigation of the Acoustically Excited Subsonic Turbulent Coanda Air Flow Field Around a Circular Cylinder written by Richard E. Harkness and published by . This book was released on 1969 with total page 256 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeroacoustic Investigation and Adjoint Analysis of Subsonic Cavity Flows written by Laia Moret-Gabarro and published by . This book was released on 2009 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unsteady flow over surface discontinuities produces high aerodynamic noise. The aim of this thesis is to study the aeroacoustics of two-dimensional rectangular cavities and to find strategies for noise reduction. Direct Numerical Simulation of the compressible Navier-Stokes equations is performed to investigate the influence of the initial condition on the oscillation modes in deep and shallow cavities. Results show that the deep cavity oscillates in shear layer regime at the second Rossiter mode regardless of the initial condition. On the other hand different initial conditions lead to a shear layer or wake mode in the shallow cavity case. A sensitivity analysis of the deep cavity is done by the use of adjoint methods. Local sinusoidal perturbations of x-momentum and density are applied to the adjoint equations. The results show a high sensitivity region to mass injection at the upstream corner. Therefore an actuator placed at the leading edge will modify the velocity fluctuations reaching the trailing edge and hence the pressure fluctuations in the far-field.
Download or read book An Experimental Investigation of the Possible Frequency Effects of a Vibrating Wall on the Boundary Layer Heat Transfer for Subsonic Flow Parallel to the Wall written by John Irvin McDougal and published by . This book was released on 1962 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of a Side Branch Resonator in a Flow Duct written by Shantel Hansen and published by . This book was released on 1998 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
