Foundational terms in aerospace engineering — the shared vocabulary of aeronautics and astronautics.

Fluid dynamics

  • Atmosphere — the gaseous envelope whose properties vary with altitude
  • Viscosity — a fluid’s resistance to shearing motion, creating boundary layers and governing Reynolds number
  • Laminar and Turbulent Flow — the two fundamental states of fluid flow
  • Flow Separation — detachment of the boundary layer, the mechanism behind stall and pressure drag
  • Bernoulli Equation — the pressure-velocity relationship in incompressible flow
  • Dynamic Pressure — ½ρv², governing aerodynamic forces and structural loads
  • Navier-Stokes Equations — the fundamental equations of viscous fluid motion

Flight mechanics

  • Airspeed — the speed relative to the surrounding air mass
  • Mach Number — velocity relative to the speed of sound, defining compressibility regime
  • Center of Pressure — the point where aerodynamic forces act, governing stability
  • Stability — the tendency to return to equilibrium after disturbance
  • Thrust — the reaction force from accelerating a working fluid

Structural mechanics

  • Stress — internal force per unit area within a material
  • Strain — deformation per unit length under load
  • Young’s Modulus — the ratio of stress to strain, measuring material stiffness
  • Yield Strength — the stress at which permanent deformation begins
  • Bending Moment — internal moment from transverse loads, the dominant wing load
  • Shear Force — internal force perpendicular to a member’s axis
  • Torsion — twisting load about a member’s longitudinal axis
  • Structural Load — forces and moments the vehicle structure must withstand

Environment and thermodynamics

  • Heat Transfer — conduction, convection, and radiation in aerospace thermal design
  • Shock Wave — abrupt pressure discontinuity in supersonic flow
  • Orbital Mechanics — the physics of motion under gravitational attraction