Author: National Aeronautics and Space Adm Nasa

Publisher: Independently Published

Published: 2018-09-23

Total Pages: 84

ISBN-13: 9781723962981

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