Download or read book Flow Induced Resonance of Screen Covered Cavities written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-03 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of screen-covered cavities exposed to airflow tangent to the screen is described. The term screen refers to a thin metal plate perforated with a repetitive pattern of round holes. The purpose was to find the detailed aerodynamic and acoustic mechanisms responsible for screen-covered cavity resonance and to find ways to control the pressure oscillations. Results indicate that strong cavity acoustic resonances are created by screen orifices that shed vortices which couple resonance by choosing hole spacings such that shed vortices do not arrive at a downstream orifice in synchronization with cavity pressure oscillations. The proper hole pattern is effective at all airspeeds. It was also discovered that a reduction of orifice size tended to weaken the screen/cavity interaction regardless of hole pattern, probably because of viscous flow losses at the orifices. The screened cavities that resonated did so at much higher frequencies than the equivalent open cavity. The classical large eddy phenomenon occurs at the relatively small scale of the orifices (the excitation is typically of high frequency). The wind tunnel study was made at airspeeds from 0 to 100m/sec. The 457-mm-long by 1.09-m-high rectangular cavities had length-to-depth ratios greater than one, which is indicative of shallow cavities. The cavity screens were perforated in straight rows and columns with hole diameters ranging from 1.59 to 6.35 mm and with porosities from 2.6 to 19.6 percent. Soderman, Paul T. Ames Research Center RTOP 505-61-11...

Download or read book Flow induced Resonance of Screen covered Cavities written by Paul T. Soderman and published by . This book was released on 1990 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Flow induced Resonance of Screen covered Cavities Oct 1990 written by and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Paper written by and published by . This book was released on 1990 with total page 62 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Experimental Investigation of Flow induced Cavity Resonance written by Paul Zoccola (Jr., J.) and published by . This book was released on 2000 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Scientific and Technical Publications written by and published by . This book was released on 1993 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Scientific and Technical Publications A Catalog of Special Publications Reference Publications Conference Publications and Technical Papers 1991 1992 written by and published by . This book was released on 1993 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1992 with total page 888 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Studies of the Mechanism for the Flow induced Cavity Resonance written by M. C. Harrington and published by . This book was released on 1960 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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).

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1992 with total page 1622 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Archives of Acoustics Quarterly written by and published by . This book was released on 2018 with total page 772 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Active Control of Flow induced Cavity Resonance written by L. Mongeau and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA SP written by and published by . This book was released on 1962 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Review of Active Control of Flow induced Cavity Resonance written by Louis Cattafesta and published by . This book was released on 2003 with total page 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 1991 with total page 1332 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Aeronautical Journal written by and published by . This book was released on 1991 with total page 452 pages. Available in PDF, EPUB and Kindle. Book excerpt: