Principles of Glider DesignPrinciples of Glider Design

Mark LesmeisterMark Lesmeister

Dawson HS PhysicsDawson HS Physics

Understanding LiftUnderstanding Lift

Lift can be understood Lift can be understood using either Newtonian using either Newtonian Mechanics or Mechanics or Bernoulli’s Principle.Bernoulli’s Principle.

Bernoulli’s PrincipleBernoulli’s Principle

Understanding LiftUnderstanding Lift

A wing speeds up and A wing speeds up and slows down the flow of slows down the flow of the fluid in different the fluid in different places, causing the places, causing the pressure to differ in pressure to differ in different directions. different directions.

Understanding LiftUnderstanding Lift

A wing exerts a force A wing exerts a force in the downward in the downward direction on air, so the direction on air, so the air exerts a net upward air exerts a net upward force. force.

Lift EquationLift Equation

The lift depends on The lift depends on many factors, some of many factors, some of which you cannot which you cannot control.control.

The Lift EquationThe Lift Equation

So the faster speed, So the faster speed, the more lift. However, the more lift. However, your gliders will lose your gliders will lose speed as drag slows speed as drag slows them down.them down.

A larger wing area A larger wing area improves lift. improves lift. However, it also However, it also increases drag.increases drag.

The Lift EquationThe Lift Equation

The lift coefficient The lift coefficient includes numerous includes numerous factors, and is usually factors, and is usually experimentally experimentally determined. determined.

Two that you control Two that you control are inclination and are inclination and shape.shape.

Angle of AttackAngle of Attack

The angle the wing makes relative to the The angle the wing makes relative to the oncoming airflow is the angle of attack.oncoming airflow is the angle of attack.

Angle of AttackAngle of Attack

The angle the wing makes relative to the The angle the wing makes relative to the oncoming airflow is the angle of attack.oncoming airflow is the angle of attack.