Aerodynamics characteristics of glider GL-1 based on computational fluid dynamics

Abstract

Glider GL-1 was especially designed for thermal updraft condition of Indonesia. The development of GL-1 is the first in Indonesia to design a glider for aero sport purpose in cooperation with FASI. This glider needs a minimum aerodynamics efficiency of 8.333 to meet design requirement derived from thermal updraft condition, which needs rate of descent little than 3 m/s at gliding angle of 2 degree. Optimum flight condition for maximum range performance has been calculated to be 25 m/s at a condition of altitude between 300 - 2000 m with Reynolds number of 1 - 1.5 million. Computational Fluid Dynamics (CFD) was employed to do numerical analyses to predict aerodynamics characteristics of the glider. CFD by using half-glider meshing results maximum lift coefficient of 1.326 at angle of attack of 8 degree, and maximum aerodynamics efficiency of 19 at angle of attack 2 degree. The result of CFD by using full-glider meshing gives maximum lift coefficient of 1.2556 at angle of attack of 10 degree and maximum aerodynamics efficiency of 16 at angle of attack of 2 degree. Both of half-glider meshing and full-glider meshing are employing k-ϵ turbulence model. Comparison with preliminary design result and benchmarking with similar gliders data was also done.