Download or read book Aerodynamics of a Linear Oscillating Cascade written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-23 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: The steady and unsteady aerodynamics of a linear oscillating cascade are investigated using experimental and computational methods. Experiments are performed to quantify the torsion mode oscillating cascade aerodynamics of the NASA Lewis Transonic Oscillating Cascade for subsonic inlet flowfields using two methods: simultaneous oscillation of all the cascaded airfoils at various values of interblade phase angle, and the unsteady aerodynamic influence coefficient technique. Analysis of these data and correlation with classical linearized unsteady aerodynamic analysis predictions indicate that the wind tunnel walls enclosing the cascade have, in some cases, a detrimental effect on the cascade unsteady aerodynamics. An Euler code for oscillating cascade aerodynamics is modified to incorporate improved upstream and downstream boundary conditions and also the unsteady aerodynamic influence coefficient technique. The new boundary conditions are shown to improve the unsteady aerodynamic influence coefficient technique. The new boundary conditions are shown to improve the unsteady aerodynamic predictions of the code, and the computational unsteady aerodynamic influence coefficient technique is shown to be a viable alternative for calculation of oscillating cascade aerodynamics. Buffum, Daniel H. and Fleeter, Sanford Glenn Research Center NASA-TM-103250, E-5677, NAS 1.15:103250 RTOP 535-05-01...
Download or read book Aerodynamics of a Linear Oscillating Cascade written by and published by . This book was released on 1990 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Comparison of Theoretical and Experimental Unsteady Aerodynamics of Linear Oscillating Cascade with Supersonic Leading Edge Locus written by Nasa Technical Reports Server (Ntrs) and published by BiblioGov. This book was released on 2013-07 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental influence coefficient technique was used to obtain unsteady aerodynamic influence coefficients and, consequently, unsteady pressures for a cascade of symmetric airfoils oscillating in pitch about mid-chord. Stagger angles of 0 deg and 10 deg were investigated for a cascade with a gap-to-chord ratio of 0.417 operating at an axial Mach number of 1.9, resulting in a supersonic leading-edge locus. Reduced frequencies ranged from 0.056 to 0.2. The influence coefficients obtained determine the unsteady pressures for any interblade phase angle. The unsteady pressures were compared with those predicted by several algorithms for interblade phase angles of 0 deg and 180 deg.
Download or read book Comparison of Theoretical and Experimental Unsteady Aerodynamics of Linear Oscillating Cascade with Supersonic Leading Edge Locus written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-29 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental influence coefficient technique was used to obtain unsteady aerodynamic influence coefficients and, consequently, unsteady pressures for a cascade of symmetric airfoils oscillating in pitch about mid-chord. Stagger angles of 0 deg and 10 deg were investigated for a cascade with a gap-to-chord ratio of 0.417 operating at an axial Mach number of 1.9, resulting in a supersonic leading-edge locus. Reduced frequencies ranged from 0.056 to 0.2. The influence coefficients obtained determine the unsteady pressures for any interblade phase angle. The unsteady pressures were compared with those predicted by several algorithms for interblade phase angles of 0 deg and 180 deg.Ramsey, John K. and Erwin, DanGlenn Research CenterUNSTEADY AERODYNAMICS; INFLUENCE COEFFICIENT; PRESSURE MEASUREMENT; PRESSURE OSCILLATIONS; WIND TUNNEL TESTS; CASCADE FLOW; MACH NUMBER; SUPERSONIC FLUTTER; AIRFOIL OSCILLATIONS; PRESSURE DISTRIBUTION; SUPERSONIC WIND TUNNELS
Download or read book Effect of Wind Tunnel Acoustic Modes on Linear Oscillating Cascade Aerodynamics written by Daniel H. Buffum and published by . This book was released on 1993 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Aerodynamics Aeroacoustics and Aeroelasticity of Turbomachines and Propellers written by H.M. Atassi and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 876 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first International Symposium on Unsteady Aerodynamics and Aero elasticity of Turbomachines was held in Paris in 1976, and was followed by symposia at Lausanne in 1980, Cambridge in 1984, Aachen in 1987, Bei jing in 1989, and Notre Dame in 1991. The proceedings published following these symposia have become recognized both as basic reference texts in the subject area and as useful guides to progress in the field. It is hoped that this volume, which represents the proceedings of the Sixth International Symposium on Unsteady Aerodynamics of Turbomachines, will continue that tradition. Interest in the unsteady aerodynamics, aeroacoustics, and aeroelasticity of turbomachines has been growing rapidly since the Paris symposium. This expanded interest is reflected by a significant increase in the numbers of contributed papers and symposium participants. The timeliness of the topics has always been an essential objective of these symposia. Another important objective is to promote an international exchange between scien tists and engineers from universities, government agencies, and industry on the fascinating phenomena of unsteady turbomachine flows and how they affect the aeroelastic stability of the blading system and cause the radiation of unwanted noise. This exchange acts as a catalyst for the development of new analytical and numerical models along with carefully designed ex periments to help understand the behavior of such systems and to develop predictive tools for engineering applications.
Download or read book Oscillating Cascade Aerodynamics at Large Mean Incidence written by Daniel H. Buffman and published by . This book was released on 1996 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Presented at the International Gas Turbine and Aeroengine Congress & Exhibition Birmingham, UK - June 10-13, 1996.
Download or read book An Experimental Study on the Aerodynamic Response of a Subsonic Cascade Oscillating Near Stall written by Franklin O. Carta and published by . This book was released on 1976 with total page 107 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were performed on a linear cascade of airfoils oscillating in pitch about their midchords at frequencies up to 17 cps, at velocities up to 200 ft/sec and at interblade phase angles of 0 and 45 deg, under conditions of high aerodynamic loading. The measured data included unsteady time histories from chordwise pressure transducers and chordwise hot films. Unsteady normal force coefficient, moment coefficient, and aerodynamic work per cycle of oscillation were obtained from integrals of the pressure data, and indications of the nature and extent of the separation phenomenon were obtained from an analysis of the hot film response data. The most significant finding of this investigation is that a change in interblade phase angle from 0 deg to 45 deg radically alters the character of the blade loading (which governs its motion in a free system) from stable to unstable. Furthermore, the stability or instability is governed primarily by the phase angle of the pressure distribution over the forward 10 to 15 percent of the blade chord. Reduced frequency and mean incidence angle changes were found to have a relatively minor effect on stability for the range of parameters tested. (Author).
Download or read book A Linear Aerodynamic Analysis for Unsteady Transonic Cascades written by Joseph M. Verdon and published by . This book was released on 1984 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: A potential flow analysis to predict unsteady airloads produced by the vibrations of turbomachinery blades operating at transonic Mach numbers is presented. The unsteady aerodynamic model includes the effects of blade geometry, finite mean pressure variation across the blade row, high frequency blade motion, and shock motion within the framework of a linearized, frequency domain formulation. The unsteady equations are solved implicit, least squares, finite difference approximation which is applicable on arbitrary grids. A numerical solution for the entire unsteady field is determined by matching a solution determined on a rectilinear type cascade mesh, which covers an extended blade passage region, to a solution determined on a detailed polar type local mesh, which covers and extends well beyond the supersonic region(s) adjacent to a blade surface. Cascades of double circular arc and flat plate blades demonstrate the unsteady analysis, and partially illustrate the effects of blade geometry, inlet Mach number, blade vibration frequency and shock motion on unsteady response.
Download or read book Aerodynamics of Cascaded Airfoils Oscillating Or Subject to Three Dimensional Periodic Gusts written by H. Atassi and published by . This book was released on 1980 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three problems which have been investigated are discussed in this report. Aerodynamic theory and computational procedures have been developed to study the aeroelastic stability of oscillating loaded airfoils in cascade with interblade phase angle. Contrary to linear theory, results show that classical flutter can occur for low speed turbine cascades operating at typical design conditions. Ground effects on fan inlet flows were investigated based on data from NASA - Lewis. The analysis showed that swirling flows are the dominant source of flow disturbances entering the fan. Finally, a study was made of three-dimensional periodic disturbances acting upon loaded airfoils in cascade. (Author).
Download or read book Development of an Unsteady Aerodynamic Analysis for Finite deflection Subsonic Cascades written by Joseph M. Verdon and published by . This book was released on 1981 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental and Computational Investigation of Oscillating Airfoil Unsteady Aerodynamics at Large Mean Incidence written by and published by DIANE Publishing. This book was released on 2003 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Linear Aerodynamic Analysis for Unsteady Transonic Cascades written by Joseph M. Verdon and published by . This book was released on 1984 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Aerodynamics and Aeroelasticity of Turbomachines written by Torsten H. Fransson and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 835 pages. Available in PDF, EPUB and Kindle. Book excerpt: Twenty-one years have passed since the first symposium in this series was held in Paris (1976). Since then there have been meetings in Lausanne (1980), Cambridge (1984), Aachen (1987), Beijing (1989), Notre Dame (1991) and Fukuoka (1994). During this period a tremendous development in the field of unsteady aerodynamics and aeroelasticity in turbomachines has taken place. As steady-state flow conditions become better known, and as blades in the turbomachine are constantly pushed towards lower weight, and higher load and efficiency, the importance of unsteady phenomena appear more clearly. th The 8 Symposium was, as the previous ones, of high quality. Furthermore, it presented the audience with the latest developments in experimental, numerical and theoretical research. More papers than ever before were submitted to the conference. As the organising committee wanted to preserve the uniqueness of the symposium by having single sessions, and thus mingle speakers and audience with different backgrounds in this interdisciplinary field, only a limited number of papers could be accepted. 54 papers were accepted and presented at the meeting, all of which are included in the present proceedings.
Download or read book Design and Development of Aerospace Vehicles and Propulsion Systems written by S. Kishore Kumar and published by Springer Nature. This book was released on 2021-03-18 with total page 529 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents selected papers presented in the Symposium on Applied Aerodynamics and Design of Aerospace Vehicles (SAROD 2018), which was jointly organized by Aeronautical Development Agency (the nodal agency for the design and development of combat aircraft in India), Gas-Turbine Research Establishment (responsible for design and development of gas turbine engines for military applications), and CSIR-National Aerospace Laboratories (involved in major aerospace programs in the country such as SARAS program, LCA, Space Launch Vehicles, Missiles and UAVs). It brings together experiences of aerodynamicists in India as well as abroad in Aerospace Vehicle Design, Gas Turbine Engines, Missiles and related areas. It is a useful volume for researchers, professionals and students interested in diversified areas of aerospace engineering.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Unsteady Aerodynamics Aeroacoustics and Aeroelasticity of Turbomachines written by Kenneth C. Hall and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 605 pages. Available in PDF, EPUB and Kindle. Book excerpt: This textbook is a collection of technical papers that were presented at the 10th International Symposium on Unsteady Aerodynamics, Aeroacoustics, and Aeroelasticity of Turbomachines held September 8-11, 2003 at Duke University in Durham, North Carolina. The papers represent the latest in state of the art research in the areas of aeroacoustics, aerothermodynamics, computational methods, experimental testing related to flow instabilities, flutter, forced response, multistage, and rotor-stator effects for turbomachinery.
