Download or read book An Investigation of a Simplified Rotor Wake Model and Its Effects on Harmonic Airloading written by Stephen C. Ellis and published by . This book was released on 1983 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Rotor Wake Geometry and Its Influence in Forward Flight Volume 1 Generalized Wake Geometry and Wake Effect on Rotor Airloads and Performance written by T. A. Egolf and published by . This book was released on 1983 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytic investigation to generalize wake geometry of a helicopter rotor in steady level forward flight and to demonstrate the influence of wake deformation in the prediction of rotor airloads and performance is described. Volume 1 presents a first level generalized wake model based on theoretically predicted tip vortex geometries for a selected representative blade design. The tip vortex distortions are generalized in equation form as displacements from the classical undistorted tip vortex geometry in terms of vortex age, blade azimuth, rotor advance ratio, thrust coefficient, and number of blades. These equations were programmed to provide distorted wake coordinates at very low cost for use in rotor airflow and airloads prediction analyses. The sensitivity of predicted rotor airloads, performance, and blade bending moments to the modeling of the tip vortex distortion are demonstrated for low to moderately high advance ratios for a representative rotor and the H-34 rotor. Comparisons with H-34 rotor test data demonstrate the effects of the classical, predicted distorted, and the newly developed generalized wake models on airloads and blade bending moments. Use of distorted wake models results in the occurrence of numerous blade-vortex interactions on the forward and lateral sides of the rotor disk. The significance of these interactions is related to the number and degree of proximity to the blades of the tip vortices. The correlation obtained with the distorted wake models (generalized and predicted) is encouraging.

Download or read book An Investigation of the Quantitative Applicability of Model Helicopter Rotor Wake Patterns Obtained from a Water Tunnel written by Anton J. Landgrebe and published by . This book was released on 1971 with total page 142 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analytical investigation was conducted to evaluate quantitative applications of available model rotor tip vortex patterns from a water tunnel. This evaluation consisted of reducing selected photographic wake data to coordinate form, and comparing the resulting wake geometries with both theoretical results and available experimental data taken in air. Additionally, the study included an examination of the sensitivity of water tunnel wake geometry to the water tunnel test parameters which did not duplicate full-scale rotor values and the applicability of a water tunnel wake geometry to determine the airloads of a full-scale rotor. Finally, the possibility of developing simplified wake documentation and generalization procedures and improved water tunnel test techniques was assessed. (Author).

Download or read book Computation of Helicopter Rotor Wake Geometry and Its Influence on Rotor Harmonic Airloads written by Michael P. Scully and published by . This book was released on 1975* with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Computation on helicoptor rotor wake geometry and its influence on rotor harmonic airloads written by Michael Patrick Scully and published by . This book was released on 1975 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Vertica written by and published by . This book was released on 1981 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Helicopter Rotor Wake Geometry and Airloads and Helicopter Rotor Wakes written by M. P. Scully and published by . This book was released on 1972 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: Computer programs have been developed for the calculation of helicopter rotor tip vortex geometry in hover and forward flight and for the calculation of helicopter rotor harmonic airloads in forward flight. Calculated forward flight tip vortex geometries compare well in general with experimental smoke studies although there are differences in detail. The hovering tip vortex geometry agrees qualitatively with experiment but does not move downward fast enough. Airloads were computed using both the classical rigid wake assumption and the distorted tip vortex geometry obtained from the computer program. When compared with experimental airloads measurements the rigid wake airloads give better results than the distorted wake airloads. (Author).

Download or read book A Rotor Wake Model for Forward Flight Simulation Studies written by K. R. Reddy and published by . This book was released on 1981 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Note presents an attempt to develop a rotor wake model for forward flight which requires only modest computing time and, therefore, is suitable for flight simulation studies. Free and rigid wake models are discussed, together with various simplifying assumptions, in order to reduce the computation time to acceptable levels for simulation studies. Using a tip vortex wake model and the Biot-Savart relation, induced velocities are calculated in the rotor plane. It is then assumed that the tip vortex wake takes the form of a skewed helix. Such a simple prescribed model requires little computing time and the accuracy of its results when compared with more elaborate free wake models shows considerable promise. (Author).

Download or read book Rotorcraft Dynamics written by and published by . This book was released on 1974 with total page 384 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Royal Aeronautical Society written by and published by . This book was released on 1964 with total page 1020 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Wind Engineering 1983 written by J. D. Holmes and published by . This book was released on 1984 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book International Aerospace Abstracts written by and published by . This book was released on 1984 with total page 922 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the American Helicopter Society written by and published by . This book was released on 1966 with total page 1152 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 1974 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Aeroacoustics of Flight Vehicles written by Harvey H. Hubbard and published by . This book was released on 1991 with total page 620 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Free Wake Techniques for Rotor Aerodynamic Analysis Volume 1 Summary of Results and Background Theory written by and published by . This book was released on 1982 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Index Aeronauticus written by and published by . This book was released on 1967 with total page 736 pages. Available in PDF, EPUB and Kindle. Book excerpt: