Download or read book A Comparison of the Acoustic and Aerodynamic Measurements of a Model Rotor Tested in Two Anechoic Wind Tunnels written by and published by . This book was released on 1986 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Comparison of the Acoustic and Aerodynamic Measurements of a Model Rotor Tested in Two Anecholic Wind Tunnels written by D. A. Boxwell and published by . This book was released on 1986 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two aeroacoustic facilities--the CEPRA 19 in France and the DNW in the Netherlands--are compared. The two facilities have unique acoustic characterists that make them appropriate for acoustic testing of model-scale helicopter rotors. An identical pressure-instrumented model-scale rotor was tested in each facility and acoustic test lresults are compared with full-scale rotor test results. Blade surface pressures measured in both tunnels were used to correlate nominal rotor operating conditions in each tunnel, and also used to assess the steadiness of the rotor in each tunnel's flow. In-the-flow rotor acoustic signatures at moderate forward speeds (35-50 m/sec) are presented for each facility and discussed in relation to the differences in tunnel geometries and aeroacoustic characteristics. Keywords: Acoustics; Anechoic wind tunnels; Model helicopter rotors; Blade pressures.
Download or read book NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1988 with total page 256 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 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Preliminary Study of a Model Rotor in Descent written by and published by . This book was released on 2000 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt: Within a program designed to develop experimental techniques for measuring the trajectory and structure of vortices trailing from the tips of rotor blades, the present preliminary study focuses on a method for quantifying the trajectory of the trailing vortex during descent flight conditions. This study also presents rotor loads and blade surface pressures for a range of tip-path plane angles and Mach numbers. Blade pressures near the leading edge and along the outer radius are compared with data obtained on the same model rotor, but in open jet facilities. A triangulation procedure based on two directable laser-light sheets, each containing an embedded reference, proved effective in defining the spatial coordinates of the trailing vortex. When interrogating a cross section of the flow that contains several trailing vortices, the greatest clarity was found to result when the flow is uniformly seeded. Surface pressure responses during blade-vortex interactions appeared equally sensitive near the leading edge and along the outer portion of the blade, but diminished rapidly as the distance along the blade chord increased. The pressure response was virtually independent of whether the tip-path plane angle was obtained through shaft tilt or cyclic pitch. Although the shape and frequency of the pressure perturbations on the advancing blade during blade-vortex interaction are similar to those obtained in open-jet facilities, the angle of the tip-path plane may need to be lower than the range covered in this study.
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 Handbook of Engineering Acoustics written by Gerhard Müller and published by Springer Science & Business Media. This book was released on 2012-11-06 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt: This acoustics handbook for mechanical and architectural applications is a translation of the German standard work on the subject. It not only describes the state of art of engineering acoustics but also gives practical help to engineers for solving acoustic problems. It deals with the origin, the transmission and the methods of abatement of air-borne and structure-borne sound of different kinds, from traffic to machinery and flow induced sound.
Download or read book Army R D A written by and published by . This book was released on 1982-07 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Army RD A Bulletin written by and published by . This book was released on 1982 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering written by and published by . This book was released on 1991 with total page 538 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Army RD A written by and published by . This book was released on 1982 with total page 664 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 1992 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Tech Briefs written by and published by . This book was released on 1991-08 with total page 72 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 1991-03 with total page 954 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 1654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index Keyword A L written by and published by . This book was released on 1987 with total page 974 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Army Rotorcraft Technology Volume 2 Materials and Structures Propulsion and Drive Systems Flight Dynamics and Control and Acoustics written by and published by . This book was released on 1988 with total page 596 pages. Available in PDF, EPUB and Kindle. Book excerpt:
