Aerodynamics

Aerodynamics studies air and other gases in motion and the forces they exert on objects. It explains how pressure, flow, and viscosity shape lift, drag, and stability.

Boundary layer: A thin region near a surface where viscosity strongly affects fluid velocity. Its behavior governs skin friction and whether flow separates from wings and bodies.
Fluid mechanics: The study of fluids at rest and in motion, including liquids and gases. Aerodynamics is its branch focused on gases and moving bodies.
Airfoil: A shaped cross-section designed to generate aerodynamic forces as fluid flows around it. Its geometry sets the lift and drag characteristics of wings and blades.
Hydrodynamics: The study of liquids in motion and the forces they exert. It shares fluid-mechanical foundations but focuses on liquids rather than gases.
Daniel Bernoulli: A Swiss mathematician and physicist whose work connected fluid speed with pressure. His principle became a foundational tool for interpreting pressure in moving air.
Lift: The component of aerodynamic force perpendicular to an object's relative airflow. Pressure and momentum changes in the surrounding flow produce this force.
Navier–Stokes equations: Differential equations describing the motion of viscous fluids through conservation of momentum. They form the governing equations for most continuous-flow aerodynamic models.
Wing: A surface that generates aerodynamic force to support or control an aircraft. Wings apply airfoil principles across a span to produce lift.
Subsonic flight: Flight at speeds below the local speed of sound. Its flow usually avoids the shock waves characteristic of supersonic flight.
George Cayley: An English engineer who identified lift, drag, and thrust as distinct forces in flight. His analysis helped turn flight from imitation of birds into an engineering problem.

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