Download or read book Design of a Hovering Rotor Using Full potential Equations Free wake and Optimization written by Frank Patrick Driscoll and published by . This book was released on 1993 with total page 308 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 427 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS)* at Purdue University in 1957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dis semination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all concerned if the printing and distribution of the volumes were handled by an international publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Corporation of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 39 (thesis year 1994) a total of 13,953 thesis titles from 21 Canadian and 159 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this impor tant annual reference work. While Volume 39 reports theses submitted in 1994, on occasion, certain uni versities do report theses submitted in previous years but not reported at the time.

Download or read book Performance Optimization for Rotors in Hover and Axial Flight written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Performance optimization for rotors in hover and axial flight is a topic of continuing importance to rotorcraft designers. The aim of this Phase 1 effort has been to demonstrate that a linear optimization algorithm could be coupled to an existing influence coefficient hover performance code. This code, dubbed EHPIC (Evaluation of Hover Performance using Influence Coefficients), uses a quasi-linear wake relaxation to solve for the rotor performance. The coupling was accomplished by expanding of the matrix of linearized influence coefficients in EHPIC to accommodate design variables and deriving new coefficients for linearized equations governing perturbations in power and thrust. These coefficients formed the input to a linear optimization analysis, which used the flow tangency conditions on the blade and in the wake to impose equality constraints on the expanded system of equations; user-specified inequality contraints were also employed to bound the changes in the design. It was found that this locally linearized analysis could be invoked to predict a design change that would produce a reduction in the power required by the rotor at constant thrust. Thus, an efficient search for improved versions of the baseline design can be carried out while retaining the accuracy inherent in a free wake/lifting surface performance analysis. Quackenbush, T. R. and Wachspress, D. A. and Kaufman, A. E. and Bliss, D. B. Unspecified Center NAS2-12789; RTOP 505-61-51...

Download or read book Rotor Design Optimization Using a Free Wake Analysis written by and published by . This book was released on 1993 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Results of the Integration of a Transonic Full potential Analysis Program with a Free wake Lifting line Program for Hovering Rotors written by and published by . This book was released on 1987 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Free Wake Computation of Helicopter Rotor Flowfield for General Flight Regimes written by and published by . This book was released on 1992 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt: A CFD based computer code, HELIX II has been developed for computing helicopter rotor flowfield in hover and in forward flight. In order to predict the vibratory airloads in forward flight and the performance in hover the effect of shed wake has to be accurately accounted for. This has been accomplished by an unique vorticity embedding procedure. The wake is convected in a Lagrangian sense and does not suffer from numerical dissipation. The effect of this convected wake is included in the Eulerian using Clebsch representation. The unsteady full potential equation is solved in the Eulerian grid with the embedded vortical velocity accounting for the influence of wake. The wake evolves as a part of the solution. Dynamic grid modifications are performed at each time step to account for blade motion and deformation. These modifications are confined to regions near the blade using suitable blending functions. In addition a vorticity confinement method is developed which involves adding a term to the momentum conservation equation of fluid dynamics. This modification is very useful in the numerical solution of flow problems involving vortical regions. The Euler equations solved with this extra term can convect vortices without Numerical dissipation. Unsteady airloads, Lagrangian wake convection, Eulerian grid, Vorticity Embedding, Clebsch representation, Vorticity confinement, Euler Equation solution without dissipation.

Download or read book Computational Fluid Dynamics Techniques written by Fathi Habashi and published by CRC Press. This book was released on 1995-11-22 with total page 930 pages. Available in PDF, EPUB and Kindle. Book excerpt: First published in 1995. Routledge is an imprint of Taylor & Francis, an informa company.

Download or read book A Full Potential Flow Analysis with Realistic Wake Influence for Helicopter Rotor Airload Prediction written by T. Alan Egolf and published by . This book was released on 1987 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Free Wake Analysis of Hover Performance Using a New Influence Coefficient Method written by Todd R. Quackenbush and published by . This book was released on 1990 with total page 108 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 702 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Free Wake Analysis of a Rotor in Hover written by C. S. Chen and published by . This book was released on 1987 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical method based on the axisymmetric, incompressible Navier-Stokes equations is combined with a lifting surface code to predict the vortex wake of hovering rotors. The lifting surface code, AMI Hover, is used to obtain the circulation distribution on the blade. This circulation distribution is fed into the Navier-Stokes code to compute the vortex wake under this specified circulation distribution. An iteration approach is used between these two codes to converge the circulation distribution and the shape of the vortex wake. A relaxation scheme is developed to resolve the instability encountered among the tip vortices. A reconcentration scheme is used to solve the diffusion problem due to the strong artificial viscosity. The results from the present method are compared with experimental data obtained by smoke-flow visualization and hot-wire measurements for several rotor blade configurations. The comparisons show that the present method is able to predict the complex wake system shed by a hovering rotor.

Download or read book Enhancements to a New Free Wake Hover Analysis written by and published by . This book was released on 1989 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1995 with total page 1100 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 1995 with total page 1096 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 Applied mechanics reviews written by and published by . This book was released on 1948 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Navier Stokes full Potential free Wake Method for Rotor Flows written by Mert E. Berkman and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: