Download or read book A Discrete Vortex Method for Studying the Wing Rock of Delta Wings written by Thomas G. Gainer and published by . This book was released on 2002 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Discrete Vortex Method for Studying the Wing Rock of Delta Wings written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-09-22 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: A discrete-vortex method is developed to investigate the wing rock problem associated with highly swept wings. The method uses two logarithmic vortices placed above the wing to represent the vortex flow field and uses boundary conditions based on conical flow, vortex rate of change of momentum, and other considerations to position the vortices and determine their strengths. A relationship based on the time analogy and conical-flow assumptions is used to determine the hysteretic positions of the vortices during roll oscillations. Static and dynamic vortex positions and wing rock amplitudes and frequencies calculated by using the method are generally in good agreement with available experimental data. The results verify that wing rock is caused by hysteretic deflections of the vortices and indicate that the stabilizing moments that limit wing rock amplitudes are the result of the one primary vortex moving outboard of the wing where it has little influence on the wing.Gainer, Thomas G.Langley Research CenterWING ROCK; VORTICES; FLOW DISTRIBUTION; DYNAMIC STABILITY; DELTA WINGS; STABILIZATION; SWEPT WINGS; HYSTERESIS; FLOW VELOCITY; DEFLECTION; CONICAL FLOW; BOUNDARY CONDITIONS; ANALOGIES
Download or read book A Discrete vortex Method for Studying the Wing Rock of Delta Wings written by National Aeronautics and Space Administration and published by . This book was released on 2018-08-27 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt: A discrete-vortex method is developed to investigate the wing rock problem associated with highly swept wings. The method uses two logarithmic vortices placed above the wing to represent the vortex flow field and uses boundary conditions based on conical flow, vortex rate of change of momentum, and other considerations to position the vortices and determine their strengths. A relationship based on the time analogy and conical-flow assumptions is used to determine the hysteretic positions of the vortices during roll oscillations. Static and dynamic vortex positions and wing rock amplitudes and frequencies calculated by using the method are generally in good agreement with available experimental data. The results verify that wing rock is caused by hysteretic deflections of the vortices and indicate that the stabilizing moments that limit wing rock amplitudes are the result of the one primary vortex moving outboard of the wing where it has little influence on the wing.Gainer, Thomas G.Langley Research CenterWING ROCK; VORTICES; FLOW DISTRIBUTION; DYNAMIC STABILITY; DELTA WINGS; STABILIZATION; SWEPT WINGS; HYSTERESIS; FLOW VELOCITY; DEFLECTION; CONICAL FLOW; BOUNDARY CONDITIONS; ANALOGIES...
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 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 Aeronautical Engineering A Cumulative Index to a Continuing Bibliography supplement 287 written by and published by . This book was released on 1993 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book AIAA Aerospace Sciences Meeting and Exhibit 42nd written by and published by . This book was released on 2004 with total page 590 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 Video Based Experimental Investigation of Wing Rock written by Steven Lynn Morris and published by . This book was released on 1989 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: This research developed a definitive theory on the cause of wing rock. The study was based on dynamic measurements in both a water tunnel and a wind tunnel on a sharp-edged delta wing with an 80 deg. leading-edge sweep angle. Experimental data were compared with analytical results from a mathematical model and a fourth order Runge-Kutta integration. In the water tunnel tests, conducted at alpha = 35 deg. and Reynolds numbers from 30000/ft to 75000/ft, the movement of the leading-edge vortices and the model motion were simultaneously tracked and analyzed using a video-based motion analysis system, ExpertVision. The initial phase of the study validated ExpertVision accuracy using stationary and forced oscillation tests on 70 deg. and 80 deg. delta wings. Vortex trajectory, core velocity, and burst point results from stationary tests were in good agreement with published data. Forced oscillation tests proved that ExpertVision could simultaneously track and analyze the movement of leading-edge vortices and model motion. Wing rock is caused by the dynamic behavior of the leading edge vortices. The alternate lift-off and reattachment of the vortices generate an asymmetry in vortex lift and cause changes in rolling moment that initiate and sustain roll oscillations. Wing rock dynamics were significantly different water tunnel and wind tunnel experiments. Apparent mass terms must be included in the equations of motion when converting water tunnel acceleration data to rolling moment coefficients; with no apparent mass correction, C sub l calculated from accelerations in the water tunnel were about 15 times greater than those from the wind tunnel. Theses. (JHD).
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering A Cumulative Index to a Continuing Bibliography supplement 300 written by and published by . This book was released on 1994 with total page 686 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Theoretical Studies on Flapped Delta Wings written by Sejong Oh and published by . This book was released on 1988 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Vortex Flow Behavior Over Slender Delta Wing Configurations written by Xing Z. Huang and published by Springer Verlag. This book was released on 2008-10-01 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book discusses the behavior of vortices over sharp and highly swept wing configurations used for current and future military aircraft. Special attention is paid to the effects of critical flow phenomenon such as vortex breakdown occuring at high angles of attack or high angular rates. The wind tunnel experiments conducted on delta-wing configurations in wind tunnels in Canada, Europe, Russia and the United States are given in eight chapters. The experiments provide an extended data base that gives insight into the effects of the angle of attack, angular rate, Reynolds number and Mach number on the behavior of vortices over several slender delta wings in stationary and instationary flights. A critical assessment is given in a separated chapter of the available experimental data bases and out of these data, one and the same data set is selected for the validation and verification of analytical and numerical solutions.Comprehansive computational results are given in another ten chapters. Steady-state and time-accurate solutions for the steady and unsteady flow over the selected delta-wing configuration are discussed. These solutions are generated using structured and unstructured grid methods.The analytical solutions for the flow over a delta wing are discussed and compared with experimental data in three more chapters.In the final chapter a validation and verification of the analytical and CFD solutions is given.
Download or read book Conical Euler Simulation and Active Suppression of Delta Wing Rocking Motion written by and published by . This book was released on 1990 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A 3 D Vortex Lattice Study of Delta Wings with and Without Dihedral and Twist written by Akbar Sultan and published by . This book was released on 1997 with total page 276 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 1993 with total page 360 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering A Cumulative Index to a Continuing Bibliography written by and published by . This book was released on 1988 with total page 516 pages. Available in PDF, EPUB and Kindle. Book excerpt:
