Glider aerodynamic design and trim optimization

Project · Project 29

Design and optimization of a high-efficiency glider configuration under mass and geometric constraints, focused on maximizing aerodynamic performance while ensuring longitudinal stability and trim conditions.

Configuration

The final configuration featured a high aspect ratio wing (AR = 30, span = 3.0 m, mass = 750 g) using an Eppler 186 airfoil for maximum aerodynamic efficiency, combined with a NACA 0010 tail configuration to minimize the drag contribution.

Three-dimensional view of the final glider configuration/assets/img/projects/glider-3d.png

Fig. 1 — Final glider geometry.

Method

Aerodynamic analysis was performed using both viscous and inviscid polars, identifying the trimmed flight conditions where maximum efficiency coincides with stable behaviour (Cm_α < 0, Cm > 0). This was achieved by optimizing the centre-of-gravity position to x = 200–215 mm, directly linking mass distribution to aerodynamic stability and performance.

Trim and efficiency curves identifying the operating point/assets/img/projects/glider-trim.png

Fig. 2 — Viscous and inviscid polars with the trimmed condition marked.

Results

Peak efficiency reached C_L/C_D = 32 under viscous conditions. The final design achieved a glide range of about 640 m and endurance of around 32 s from a 20 m altitude, at a glide angle of γ = −1.79°.

A parametric sensitivity study was additionally conducted, evaluating the impact of aspect ratio, geometric twist, tail size and tail moment arm on trim angle, range and endurance, identifying the key trade-offs between stability, efficiency and performance.