THE RESULTS OF WIND-TUNNEL TESTS AT LOW SPEEDS OF A FOUR-ENGINE PROPELLER-DRIVEN AIRPLANE CONFIGURATION HAVING A-WING WITH 40° OF SWEEPBACK AND AN ASPECT RATIO 07 10

摘要

A wind-tunnel investigation has been conducted to provide data for the study of the effects of operating propellers on the low-speed longitudinal characteristics of a four-engine tractor airplane configuration having a wing with 40° of sweepback and an aspect ratio of 10. A reflection-plane mounting was used and the semispan model represented the right-hand side of a complete hypothetical airplane. Single-rotation, right-hand propellers were operated at values of thrust coefficient ranging from 0 to 0.9 per propeller. The thrust was sufficient to simulate up to 10,000 horsepower per engine at sea level, assuming the model to be l/l2 scale. The tests were conducted at Mach numbers from 0.082 to 0.165 and Reynolds numbers of 4,000,000 to 8,000,000. Variations in the model included several heights and incidences of the horizontal tail as well as tail removed, two arrangements of extended split flaps, several propeller-blade angles, and independent as well as simultaneous operation of the inboard and outboard propellers.