Low-Speed Investigation of Upper-Surface Leading-Edge Blowing on a High-Speed Civil Transport Configuration

Low-Speed Investigation of Upper-Surface Leading-Edge Blowing on a High-Speed Civil Transport Configuration

Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-09-20

Total Pages: 64

ISBN-13: 9781723857690

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The paper identifies speed, agility, human interface, generation of sensitivity information, task decomposition, and data transmission (including storage) as important attributes for a computer environment to have in order to support engineering design effectively. It is argued that when examined in terms of these attributes the presently available environment can be shown to be inadequate. A radical improvement is needed, and it may be achieved by combining new methods that have recently emerged from multidisciplinary design optimisation (MDO) with massively parallel processing computer technology. The caveat is that, for successful use of that technology in engineering computing, new paradigms for computing will have to be developed - specifically, innovative algorithms that are intrinsically parallel so that their performance scales up linearly with the number of processors. It may be speculated that the idea of simulating a complex behaviour by interaction of a large number of very simple models may be an inspiration for the above algorithms; the cellular automata are an example. Because of the long lead time needed to develop and mature new paradigms, development should begin now, even though the widespread availability of massively parallel processing is still a few years away.Banks, Daniel W. and Laflin, Brenda E. Gile and Kemmerly, Guy T. and Campbell, Bryan A.Langley Research CenterLOW SPEED; HIGH SPEED; CIVIL AVIATION; LEADING EDGES; AERODYNAMIC CONFIGURATIONS; WIND TUNNEL TESTS; UPPER SURFACE BLOWING; DATA TRANSMISSION; MASSIVELY PARALLEL PROCESSORS; COMPUTERIZED SIMULATION; ALGORITHMS; VORTICES; WINGS


Low Speed Analysis of Mission Adaptive Flaps on a High Speed Civil Transport Configuration

Low Speed Analysis of Mission Adaptive Flaps on a High Speed Civil Transport Configuration

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

Published: 2018-06-03

Total Pages: 82

ISBN-13: 9781720616757

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Thin-layer Navier-Stokes analyses were done on a high speed civil transport configuration with mission adaptive leading-edge flaps. The flow conditions simulated were Mach = 0.22 and Reynolds number of 4.27 million for angles-of-attack ranging from 0 to 18 degrees. Two turbulence closure models were used. Analyses were done exclusively with the Baldwin-Lomax turbulence model at low angle-of-attack conditions. At high angles-of-attack where considerable flow separation and vortices occurred the Spalart-Allmaras turbulence model was also considered. The effects of flow transition were studied. Predicted aerodynamic forces, moment, and pressure are compared to experimental data obtained in the 14- by 22-Foot Subsonic Tunnel at NASA Langley. The forces and moments correlated well with experimental data in terms of trends. Drag and pitching moment were consistently underpredicted. Predicted surface pressures compared well with experiment at low angles-of-attack. Above 10 angle-of-attack the pressure comparisons were not as favorable. The two turbulent models affected the pressures on the flap considerably and neither produced correct results at the high angles-of-attack.Lessard, Victor R.Langley Research CenterTHIN FILMS; LOW SPEED; FLAPPING; TURBULENCE MODELS; PITCHING MOMENTS; MATHEMATICAL MODELS; LEADING EDGE FLAPS; BOUNDARY LAYER SEPARATION; BALDWIN-LOMAX TURBULENCE MODEL; VORTICES; TURBULENT FLOW; TRENDS; SUPERSONIC TRANSPORTS; SUBSONIC WIND TUNNELS; SEPARATED FLOW; REYNOLDS NUMBER; NAVIER-STOKES EQUATION; CLOSURE LAW; CIVIL AVIATION; AERODYNAMIC FORCES


Monthly Catalog of United States Government Publications

Monthly Catalog of United States Government Publications

Author: United States. Superintendent of Documents

Publisher:

Published: 1978

Total Pages: 1228

ISBN-13:

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February issue includes Appendix entitled Directory of United States Government periodicals and subscription publications; September issue includes List of depository libraries; June and December issues include semiannual index