Exploring the relationship between design and flight performance
Physics Investigatory Project 2025-26
This experimental study investigates how design parameters like wing shape, dihedral angle, and center of gravity affect the flight characteristics of balsa wood gliders.
This project examines the four forces of flight—lift, drag, weight, and thrust—through the construction and testing of balsa wood gliders with varying design parameters.
The primary objective is to determine how specific design elements influence flight performance metrics including distance traveled and time aloft.
Special thanks to:
Tapered wing designs will demonstrate longer flight distance and duration compared to rectangular wings.
Increased dihedral angle will improve lateral stability and flight performance.
Optimal CG position near the wing's leading edge will enhance stability.
Higher aspect ratio wings will exhibit improved aerodynamic efficiency.
Upward force opposing weight, generated by wing airfoil
Downward gravitational force on the aircraft
Forward propulsive force (absent in gliders)
Resistance opposing forward motion
Pressure decreases as fluid velocity increases, creating lift through differential pressure above and below the wing.
Leonardo da Vinci's studies of bird flight and early flying machine designs (15th-16th century)
Newton's air resistance theory (1726) and Bernoulli's fluid dynamics principle (1738)
George Cayley's identification of the four forces of flight and first wind tunnel by Francis Wenham (1871)
Wright Brothers' first powered flight (1903) leading to modern aerodynamics and CFD
The glide angle determines flying efficiency, with smaller angles enabling longer flights per altitude loss.
sin(a) = h/s
tan(a) = h/d
Where h = height, s = distance to top, d = horizontal distance flown.
| Variable | Implementation |
|---|---|
| Independent Dihedral Angle |
5 gliders with angles: 0°, 5°, 10°, 15°, 18° |
| Dependent Airtime/Distance |
Stopwatch (±0.01s) and tape measure |
| Controlled Dimensions |
Constant wing span and area across tests |
Gliders with 10-15° dihedral showed optimal performance:
Performance peaked at 15° dihedral, then declined with further increase.
| Angle | Airtime | Distance |
|---|---|---|
| 0° | 1.20 ± 0.11s | 4.8 ± 0.3m |
| 5° | 1.65 ± 0.15s | 6.2 ± 0.4m |
| 10° | 2.05 ± 0.22s | 7.8 ± 0.5m |
| 15° | 2.11 ± 0.38s | 8.4 ± 0.6m |
| 18° | 1.68 ± 0.25s | 6.7 ± 0.4m |