CFD validation of high-lift flows with significant wind-tunnel effects

Abstract

The modeling requirements for validating Navier-Stokes computations of a high-lift trapezoidal wing are investigated. This wing has a full-span slat and a full-span ap, and has been tested extensively in the NASA Langley 14-by 22-Foot Wind Tunnel and the NASA Ames 12-Foot Pressure Wind Tunnel. Due to the size of the wing, there are signi cant facility e ects in the data from the 12-Foot wind tunnel. Computational models of the test facility of di ering delity are developed and tested. Results are compared with experimental lift, drag, surface pressures, and velocity pro les. In the computations, a simpli ed, inviscid model of the test-section performs as well as a highdelity, viscous test-section model. Computed results generally compare very well with experimental data at all but the highest angles of attack. A comparison of computational results from both free-air and wind-tunnel simulations at the same lift condition indicates that it is necessary to simulate the wind-tunnel to perform validation using the 12-Foot experimental data. A subsequent grid-re nement study found that enhanced spanwise resolution increased the accuracy of the computed surface pressures at high-angle of attack, and resulted in a computed maximum lift that was 5 above the experimental value.

The aerodynamic design of multi-element high-lift systems for transport airplanes

“…However, the wall-interference corrections for wind-tunnel measurements involving high-lift configurations can be large and this may increase the uncertainties in the free-air results. In this case CFD may be required to obtain more consistent wind tunnel to free-air corrections [115].…”

A sequel to AUSM, Part II: AUSM+-up for all speeds

“…33. Rogers et al [40] have performed an extensive numerical study of the aerodynamic characteristics of this configuration using the preconditioned version of the Roe scheme in the OVERFLOW code, using the S-A one-equation model. In the present study, we used the AUSM + -up instead.…”

Comparison of Reynolds-Averaged Navier-Stokes Simulations of Multi-Element High-Lift Configurations

“…Wind-tunnel data often have large wall-interference corrections, especially for high-lift flows [6]. To validate and develop CFD methods, detailed comparison of computational results from several CFD codes and mesh topologies is helpful.…”

“…Validation studies have been conducted for a twodimensional configuration, a simplified three-dimensional configuration, and a realistic aircraft configuration. In NASA Langley, a series of simplified three-element trapezoidal high-lift wings with body pod have been tested and the experimental data are provided for validation and development of CFD methods for three-dimensional high-lift flows [4][5][6][7]. § In the Civil Transport Team of the Japan Aerospace Exploration Agency, wind-tunnel tests using a realistic aircraft takeoff and landing configuration deploying the high-lift devices with fuselage, nacelle-pylon and flap track fairing will be conducted to increase the knowledge of high-lift flows over a realistic aircraft configuration, to improve the measurement technologies, and to provide the detailed and systematic experimental data that can be disclosed for CFD validation from 2005 to 2006.…”