A unique inverting flap system has been investigated on a large-scale deflected slipstream model in the Ames 40- by 80-Foot Wind Tunnel. The subject tests utilized 33 % chord double-slotted flaps on a low-aspect ratio wing that was fully immersed in the propeller slipstream. Evaluation of the flap effectiveness is aided by comparisons with the results of tests of other flap systems on the same twin propeller, twin tail boom STOL utility aircraft mode. No extreme or abrupt force or moment increments were encountered when the flaps were deflected through a wide range, corresponding to the complete retraction/extension spectrum. The lift and descent capability of the inverting flaps compared very favorably with that of the other flap systems that have been tested on this model, including some with much greater mechanical complexity. As expected, the flaps caused large nosedown pitching-moment increments at the high lift settings however, the trimmed characteristics are still competitive with those obtained from the more complicated flap systems. It is believed that these flaps may have promising potential application to the design of relatively simple STOL utility aircraft with improved performance capabilities. In addition, they may merit consideration as retrofits to existing aircraft with less effective flap systems. (Kursetz)
Large-scale wind-tunnel tests of inverting flaps on a STOL utility aircraft model
Grossmassstab-Windtunnelversuche von Umkehrklappen an einem Modell eines Kurzstartflugzeuges
US Government Research Reports ; Jun ; 1-56
1980
56 Seiten
Report
Englisch
Design and Tests of Inverting Flaps and Wing Span Flaps
SAE Technical Papers | 1968
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