Download or read book Computational and Experimental Study of Three Dimensional Separated Flow Structure Over Prolate Spheroids written by Steven M. Harrington and published by . This book was released on 1995 with total page 318 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of Flow Over a 6 to 1 Prolate Spheroid at Incidence written by Seungki Ahn and published by . This book was released on 1992 with total page 289 pages. Available in PDF, EPUB and Kindle. Book excerpt: In two-dimensional flow, the point of flow separation from the surface coincides with the point at which the skin friction vanishes. However, in three-dimensional flow, the situation is much more complex and the flow separation is rarely associated with the vanishing of the wall shear stress except in a few special cases. Though the effects of cross-plane separation are substantial and have been recognised for some time, the phenomenon of flow separation over three-dimensional bodies is still far from being completely understood. The flow is so complex that no completely satisfactory analytical tools are available at the moment. In an attempt to logically identify the various effects and parametric dependence while simultaneously minimizing configuration dependent issue, the flow over a 6 to 1 prolate spheroid, which is a generic three-dimensional body, is investigated.
Download or read book Characterization of the Far wake of a 6 1 Prolate Spheroid written by Jonathan P. Peck and published by . This book was released on 2020 with total page 31 pages. Available in PDF, EPUB and Kindle. Book excerpt: "Even with the dramatic advances in computational power seen in the last decades, Computational Fluid Dynamics (CFD) models are as yet unable to predict transition, separation, and wake development for fluid flow over three-dimensional bodies to the desired level of accuracy in an acceptable amount of time. Without the ability to predict forces and moments experienced by the body, critical parameters such as drag and loads on control surfaces for air- and water-borne vehicles cannot be predicted. The prolate spheroid has long been a popular body upon which to verify CFD models because of its simple geometry and three-dimensional flow field. Advances in computational speed and experimental capabilities have prompted a renewed interest in related research. An experiment was conducted in the large towing tank facility of the U.S. Naval Academy, using a 6:1 prolate spheroid, measuring 54 in. (1.4 m) in length and 9 in. (0.23 m) in diameter. The spheroid model was inclined by 15° relative to the undisturbed free surface, and towed at speeds yielding length-based Reynolds numbers from 0.5-4.2 x 106. The results from the 0.5 x 106 case are presented in the present discussion. A stationary stereo particle image velocimetry (SPIV) system was designed for the experiment and used to provide two-dimensional velocity maps in two spatial-dimensions (2C2D). These time histories show the trajectory of the wake as it leaves the tail of the model, the expansion of the wake width, the size, strength, and position of the primary vortical structures shed into the wake. These results will inform follow-on studies focused on measuring turbulent quantities in the far wake." -- Report Documentation Page [Standard Form 298 (Rev. 8-98)].
Download or read book A Numerical Study of Separation on a Spheroid at Incidence written by and published by . This book was released on 1986 with total page 40 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 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Study of Separation on a Spheroid at Incidence written by M. Rosenfeld and published by . This book was released on 1986 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Computational Study of Flow Over a 6 1 Prolate Spheroid at Incidence written by Samuel Johnson and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis presents the results of computational fluid dynamics (CFD) simulations predicting the overall forces and moments acting on an inclined 6:1 prolate spheroid in crossflow. Reynolds-averaged Navier-Stokes (RANS) was used to simulate flows with Reynolds numbers ranging from 1.39 million to 4.2 million at three inclination angles, 10, 20, and 30 degrees. The RANS cases used the k-omega shear-stress-transport (SST) turbulence model, though the k-epsilon and Spalart-Allmaras models were also used for comparison in certain cases. Three mesh types: structured overset, unstructured, and trimmed Cartesian were applied to the flow cases described above and their results compared. The RANS results agreed with experimental data best at the highest Reynolds number, matching pitching moments within 3% across the range of incidence angles considered. The k-omega SST model proved the best suited of the turbulence models to accurately reproduce the flow when compared to experiments. The three turbulence models produced similar results with only marginal differences. Wall-modeled large eddy simulation (WMLES) was also used to simulate flow for the 20-degree case at a Reynolds number of 4.2 million. A grid study was carried out with the structured WMLES grids to assess the sensitivity of the wall model to initial wall spacing. The variation in initial wall spacing resulted a 5% difference in the normal force predictions as well as a 10-degree shift in the azimuthal separation location along the length of the prolate spheroid.
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 Three dimensional Separated Flow Topology written by Jean Délery and published by John Wiley & Sons. This book was released on 2013-02-28 with total page 181 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book develops concepts and a methodology for a rational description of the organization of three-dimensional flows considering, in particular, the case where the flow is the place of separations. The descriptive analysis based on the critical point theory of Poincaré develops conventional but rather unfamiliar considerations from aerodynamicists, who face the understanding of complex flows including multiple separation lines and vortices. These problems concern industrial sectors where aerodynamics plays a key role, such as aerospace, ground vehicles, buildings, etc. Contents 1. Skin Friction Lines Pattern and Critical Points. 2. Separation Streamsurfaces and Vortex Structures. 3. Separated Flow on a Body. 4. Vortex Wake of Wings and Slender Bodies. 5. Separation Induced by an Obstacle or a Blunt Body. 6. Reconsideration of the Two-Dimensional Separation. 7. Concluding Remarks. About the Authors Jean Délery is a Supaero (French National Higher School of Aeronautics and Space) engineer who has worked at Onera (French national aerospace research center) since 1964. He has participated in several major French and European aerospace programs, is the author of many scientific publications, and has occupied various teaching positions particularly at Supaero, the University of Versailles-Saint-Quentin, Ecole polytechnique in France and “La Sapienza” University in Rome, Italy. He is currently emeritus adviser at Onera.
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 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 Experimental Study of Vortical Features in Three Dimensional Separated Flows written by H. Bippes and published by . This book was released on 1984 with total page 21 pages. Available in PDF, EPUB and Kindle. Book excerpt: Possible topological structures of three-dimensional separated flows are studied on a hemisphere-cylinder at incidence. By means of a systematic variation of flow parameters a manifold of skin-friction patterns is produced. It is established that they develop from three basic structures simply by successive splitting of saddles in saddle-node-saddle combinations. The adjoining spatial flow field is visualized in low Reynolds number water tunnel flow, where similar kind of skin friction pattern develops as in fully turbulent flow. Velocity field measurements in the separated region on a rectangular wing indicate that on both models a similar topological structure, including unsteady effects, is possible. (Author).
Download or read book NASA SP written by and published by . This book was released on 1991 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Emergence of Three dimensional Separation Over Suddenly started Prolate Spheroid at Incidence written by Tzuyin Wu and published by . This book was released on 1991 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Physics of Separated Flows Numerical Experimental and Theoretical Aspects written by Klaus Gersten and published by Springer Science & Business Media. This book was released on 2013-06-29 with total page 305 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains 37 contributions in which the research work is summarized which has been carried out between 1984 and 1990 in the Priority Research Program "Physik abgeloster Stromungen" of the Deutsche Forschungsgemeinschaft (DFG, German Research Society). The aim of the Priority Research Program was the inten sive research of the whole range of phenomena associated with separated flows. Physi cal models as well as prediction methods had to be developed based on detailed experi mental investigations. It was in accordance with the main concept of the research program that scientists working on problems of separated flows in different technical areas of application participated in this program. The following fields have been represented in the program: aerodynamics of wings and bodies, aerodynamics of auto mobiles, turbomachinery, ship hydrodynamics, hydraulics, internal flows, heat exchan gers, bio-fluid-dynamics, aerodynamics of buildings and structures. In order to concentrate on problems common in all those areas the emphasis of the program was on basic research dealing with generic geometric configurations showing the fundamental physical phenomena of separated flows. The engagement and enthusiasm of all participating scientists are highly appreciated. The program was organized such that all researchers met once a year to report on the progress of their work. Special thanks ought to go to Prof. E. A. Muller (Gottingen), Prof. H. Oertel jun. (Braunschweig), Dr. W. Schmidt (Dornier), Dr. H. -W. Stock (Dornier) and Dr. B. Wagner (Dornier), who had the functions of referees on those annual meetings.
Download or read book 41st AIAA Aerospace Sciences Meeting Exhibit written by and published by . This book was released on 2003 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Engineering A Cumulative Index to a Continuing Bibliography supplement 248 written by and published by . This book was released on 1990 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt:
