In-Flight pressure measurements on a subsonic transport high-lift wing section

Abstract

The NASA Langley Transport Systems Research Vehicle (B737-100 aircraft) was used to obtain in-flight flow characteristics including surface pressures and surface shear stresses for a full-chord wing section, including the slat, main-wing, and triple-slotted, Fowler-flap elements. Chordwise pressure distributions were obtained at the 58% semispan station using thin pressure belts. Flow characteristics observed in the chordwise pressure distributions included leading-edge regions of high-subsonic flows, leading-edge attachment-line locations, slat and main-wing cove-flow separation and reattachment, and trailing-edge flow separation. In addition, surface shear-stress measurements were made using Preston-tube probes on each element. Computational analysis of the in-flight pressure measurements using two-dimensional, viscous-flow, multielement methods and simplesweep theory showed reasonable agreement. However, overprediction of the suction pressures on the flap elements indicates a need for more detailed (off-surface) measurements of the flow and the in-flight flap geometry to aid modeling of the complex three-dimensional flowfield.