Accession Number : ADP006253

Title :   The Development of Very Thick Multi-Foil Wings for High Speed, Powered Lift Transport Aircraft Applications,

Corporate Author : BOEING OF CANADA LTD DOWNSVIEW (ONTARIO) DE HAVILLAND DIV

Personal Author(s) : Farbride, J. E.

Report Date : DEC 1990

Pagination or Media Count : 20

Abstract : Motivation for the development of high speed multi-foil wings began with the Boeing Canada, de Havilland Division Powered Lift Augmentor-Wing Research Aircraft of the 1970s. This was a low speed, Ultra-Short Takeoff and Landing (USTOL) demonstrator aircraft program, which used a blown ejector (multi-foil) flap at the trailing edge of a high aspect ratio wing to provide supercirculation lift with a significant augmentation of thrust (effective reduction of drag). While the initial goal for the development of the multi-foil section was to simplify the aerodynamic/propulsion systems integration of the powered lift system for high speed flight, several aerodynamic advantages also accrued relating to the powerful control of form drag exhibited by the section. The paper briefly discusses the theoretical development of multi-foils between 18% and 30% thickness/chord and presents results from high Reynolds number, high speed, two-dimensional and three-dimensional tunnel tests on foils up to 24% thickness/chord ratio. Both blown and unblown characteristics of the foils are reviewed. The integration of these multi-foil sections into high speed advanced USTOL transport aircraft studies using the ejector flap concept has led to the potential for very efficient cruising transport aircraft with USTOL capability using only the thrust required for cruise. Finally, several other potential applications for thick multi-foil sections are briefly discussed.

Descriptors :   AERODYNAMIC FORCES, AIRCRAFT, ASPECT RATIO, AUGMENTATION, CANADA, DEMONSTRATIONS, DRAG, EJECTORS, FLAPS(CONTROL SURFACES), FLIGHT SPEEDS, HIGH RATE, HIGH VELOCITY, INTEGRATION, LOW VELOCITY, MOTIVATION, POWERED LIFT, PROPULSION SYSTEMS, REDUCTION, REYNOLDS NUMBER, TAKEOFF, TEST AND EVALUATION, THREE DIMENSIONAL, THRUST, TRAILING EDGES, TRANSPORT AIRCRAFT, TUNNELS, WINGS.

Subject Categories : Transport Aircraft
      V/STOL

Distribution Statement : APPROVED FOR PUBLIC RELEASE