Semi-tailless aircraft concept with variable cant stabilizers applied to small UAVS
Abstract
In recent years the use of small UAVs (<5lbs) has grown rapidly. While fundamentally the
same as large aircraft, differences in requirements, payloads, and cost allow for a greater number
of viable concepts. Many new concepts have been proposed however, old concepts that were never
adopted for large aircraft may be viable for small UAVs. One such concept is a semi-tailless
concept proposed by Blohm & Voss in 1944. This concept placed the stabilizer surfaces outboard
and aft of the wing tips of a highly swept main wing. This allowed for the empennage to be
removed, resulting in a reduction of empty weight and wetted area, improving a number of
performance parameters. Applying this concept to small UAVs potentially mitigate the downsides,
while providing additional opportunities. Specifically, varying the stabilizer cant angle to provide
control and improve performance. Using the basic geometry developed by Blohm & Voss, trade
studies were done to determine the stabilizer cant angle effect. A simple analytical model was used
to identify the key parameters affecting control. The configuration was then modeled with a vortex
lattice solver to predict performance. Wind tunnel and flight testing was performed to validate
predictions and provide pilot feedback on the aircraft’s behavior. It was found that the variable
cant stabilizers do allow sufficient control for most flight regimes, and small increases in
performance are possible. The results show that the concept is viable for application to small
UAVs.
Description
Thesis (M.S.)-- Wichita State University, College of Engineering, Dept. of Aerospace Engineering