The Performance of a Competition Sailplane with Variable-Toe Winglets
Open Access
Author:
Chidekel, Philip
Graduate Program:
Aerospace Engineering
Degree:
Master of Science
Document Type:
Master Thesis
Date of Defense:
March 26, 2024
Committee Members:
Amy Pritchett, Program Head/Chair Mark David Maughmer, Thesis Advisor/Co-Advisor James George Coder, Committee Member Sven Schmitz, Committee Member
Keywords:
sailplane winglets variable geometry
Abstract:
The aerodynamic design of variable-toe winglets for a 15-meter-class competition sailplane has been completed using well-validated design tools. The sailplane performance is maximized at every flight condition in both cruise and climb by properly scheduling the winglet toe angle and flap setting. These variable-toe winglets enable the sailplane to access benefits that fixed-geometry winglets compromise. It is shown that variable-toe winglets substantially improve the weak-weather cross-country performance, allowing the variable-toe sailplane to climb in weaker thermals than the unmodified sailplane can use. These gains are compelling when contextualized with contest results and other modern sailplane modifications like retractable tailwheels. Concepts for control systems, structural requirements, and certification are discussed. Finally, a preliminary investigation of flapped winglets is conducted, and it is shown that the gains produced could be even more substantial than those of variable-toe winglets, particularly in cruise.
