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 Preliminary Study of a Model Rotor in Descent written by Kenneth W. Mcalister and published by BiblioGov. This book was released on 2013-08 with total page 46 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 Preliminary Study of a Model Rotor in Descent written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-20 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.McAlister, K. W. and Tung, C. and Sharpe, D. L. and Huang, S. and Hendley, E. M.Ames Research CenterTRAJECTORIES; VORTICES; BLADE-VORTEX INTERACTION; HELICOPTER TAIL ROTORS; HELICOPTER WAKES; FLIGHT CONDITIONS; DESCENT; LOADS (FORCES); PRESSURE; FLOW VISUALIZATION; MACH NUMBER
Download or read book Devices that Alter the Tip Vortex of a Rotor written by and published by . This book was released on 2001 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: Small devices were attached near the tip of a hovering rotor blade in order to alter the structure and trajectory of the trailing vortex. Stereo particle image velocimetry (PIV) images were used to quantify the wake behind the rotor blade during the first revolution. A procedure for analyzing the 3D-velocity field is presented that includes a method for accounting for vortex wander. The results show that a vortex generator can alter the trajectory of the trailing vortex and that a major change in the size and intensity of the trailing vortex can be achieved by introducing a high level of turbulence into the core of the vortex.
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1985 with total page 898 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 1974 with total page 964 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book STAR written by and published by . This book was released on 1973 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index of NACA Technical Publications written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1953 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1960 with total page 834 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book U S Government Research and Development Reports written by and published by . This book was released on 1969 with total page 1214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advances in Communication and Computational Technology written by Gurdeep Singh Hura and published by Springer Nature. This book was released on 2020-08-13 with total page 1498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents high-quality peer-reviewed papers from the International Conference on Advanced Communication and Computational Technology (ICACCT) 2019 held at the National Institute of Technology, Kurukshetra, India. The contents are broadly divided into four parts: (i) Advanced Computing, (ii) Communication and Networking, (iii) VLSI and Embedded Systems, and (iv) Optimization Techniques.The major focus is on emerging computing technologies and their applications in the domain of communication and networking. The book will prove useful for engineers and researchers working on physical, data link and transport layers of communication protocols. Also, this will be useful for industry professionals interested in manufacturing of communication devices, modems, routers etc. with enhanced computational and data handling capacities.
Download or read book U S Government Research Development Reports written by and published by . This book was released on 1969 with total page 1208 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Research and development written by United States. Congress. Senate. Committee on Armed Services and published by . This book was released on 1973 with total page 936 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fiscal Year 1974 Authorization for Military Procurement Research and Development Construction Authorization for the Safeguard ABM and Active Duty and Selected Reserve Strengths Research and development written by United States. Congress. Senate. Committee on Armed Services and published by . This book was released on 1973 with total page 1024 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Selected Listing of NASA Scientific and Technical Reports for written by and published by . This book was released on 1949 with total page 750 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements written by and published by . This book was released on 1969 with total page 1074 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fiscal Year 1974 Authorization for Military Procurement Research and Development Construction Authorization for the Safeguard ABM and Active Duty and Selected Reserve Strengths written by United States. Congress. Senate. Committee on Armed Services and published by . This book was released on 1973 with total page 1480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
