GEOMETRY OPTIMIZATION OF PORTABLE HIGH-ALTITUDE AIRCRAFT WING

Abstract

Atmospheric conditions at high-altitudes challenges aircraft wing design. High altitude operations require high-performance solutions in air vehicle aerodynamics such as wing configuration, drag reduction, high value of lift coefficient. High-altitude aircraft developed at the moment have significant size due to those requirements. Overall goal is to overcome the storage and transportation limitations of high altitude aircraft and implement portability options. Therefore a portable high altitude aircraft wing was developed. It is necessary for the UAV to have a high value of aerodynamic quality Kmax, for maximum achievable altitude. High value of aerodynamic quality requires large wing aspect ratio λ, which is determined by the wing area and wing length. Two computational 3D model of UAV wing were made and analyzed for lift distribution over the span. To eliminate possible errors, flow calculation around the wings are executed by various aerodynamic computational methods which are panel-vortex method and finite element method. For wing profile R-III-A-15 airfoil was selected. Both wing have identical geometry parameters except the tip of second wing has an angle of -5°. Result of analyzes shows that lift distribution over the span is not optimal. Therefore further optimizations were made. Three different wing geometry designed for improving the first version of the portable high UAV wing. These are straight wing, combined wing with straight center section and trapezoid console, straight wing with elliptical tip. Those wings were compared for value of Сумах and Kмах and lift distribution over the span. Results clearly demonstrate advantages of straight wing with elliptical tip section, which allows for a continual flow of finite wings to a much greater extent than other reviewed options, which makes it possible to ensure effective control by the roll at supercritical flight conditions such as stall and tail spin. However, other important characteristics, especially Сумах and K мах have not significantly reduced compared.