Leading Edge Retraction as a High Lift Device

Author: Doss, Robert Franklin

Year: 1955

Degree: Engineer's thesis

Advisors: Stewart, Homer Joseph; Roshko, Anatol

Committee Member: Unknown, Unknown

Option: Aeronautics

DOI: 10.7907/PV47-6A63

Abstract

A two-dimensional investigation was carried out in the Merril Wind Tunnel at the California Institute of Technology to determine the effect on low speed lift of retracting the leading edge of a thin, circular-arc airfoil.

Several configurations were tried, some with a spanwise slot milled into the upper surface so that the leading edge recess formed by retraction could be utilized as an air intake to improve the flow. A comparison was made between the configurations with the leading edge retracted to various positions and the basic airfoil.

The investigation showed that leading edge retraction caused a linear loss of maximum lift proportional to the percent reduction in chord up to a critical position where lift and the stalling angle of attack increased abruptly. Thereafter, maximum lift was reduced at a rate higher than the chord reduction. The effect of the slot was negligible.

The critical position phenomenon warrants further study.

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