Introduction to Wind Engineering & Aeronautical Applications

Vocabulary flashcards covering fundamental terms, historical milestones, wind types, flight phases, aerodynamic testing tools, and engineering applications discussed in the lecture.

Wind Engineering

Interdisciplinary field that studies the effects of wind on natural and built environments, blending structural engineering, meteorology, mechanical engineering, and fluid dynamics.

Wind-Loading Chain

Analytical method introduced by Alan Garnett Davenport to evaluate how wind forces act on and are transferred through a structure.

Headwind

Wind blowing directly against an aircraft’s direction of travel, increasing ground roll and required airspeed for takeoff or landing.

Tailwind

Wind blowing in the same direction as an aircraft’s path, reducing ground roll during takeoff but increasing landing distance.

Crosswind

Wind blowing perpendicular or at an angle to the runway or flight path, creating lateral drift and higher pilot workload.

Wind Shear

Rapid change in wind speed and/or direction over a short distance, hazardous during takeoff, landing, and low-altitude flight.

Wind Gust

Sudden brief increase in wind speed that can cause abrupt changes in lift and aircraft stability.

Takeoff Phase

Critical flight segment from brake release to initial climb, highly sensitive to wind effects on lift generation and directional control.

Cruise Phase

Portion of flight at steady altitude and speed where headwinds raise fuel burn, tailwinds improve efficiency, and crosswinds cause course drift.

Landing Phase

Descent and touchdown segment requiring precise control; wind influences approach stability, touchdown point, and braking performance.

Weathercocking

Tendency of an aircraft’s nose to turn into the wind during ground roll or rotation, especially under strong crosswinds.

Crosswind Limit

Maximum demonstrated or certified crosswind component an aircraft can safely handle during takeoff or landing.

Ground Roll

Distance an aircraft travels on the runway before becoming airborne or after touchdown.

Runway Overrun

Situation where an aircraft is unable to stop before the runway end, often linked to excessive tailwind or high landing speed.

Clear Air Turbulence (CAT)

Severe turbulence occurring in cloud-free regions, typically near jet streams, without visible warning signs.

Crab Angle

Angular offset between an aircraft’s nose and its track used to counter crosswind drift during approach or cruise.

Wing-Low (Side-Slip) Technique

Crosswind landing method where the upwind wing is lowered and opposite rudder applied to keep the aircraft aligned with the runway.

LLWAS (Low-Level Wind Shear Alert System)

Ground-based sensor network that detects hazardous wind shear near airports and alerts pilots and controllers.

Wind Tunnel

Controlled facility that drives airflow past a stationary model to measure aerodynamic forces and visualize flow patterns.

Open-Circuit Wind Tunnel (Eiffel Type)

Wind tunnel that draws air from the room, passes it through the test section, and exhausts it back into the environment.

Closed-Circuit Wind Tunnel (Göttingen Type)

Energy-efficient tunnel where air circulates in a continuous loop, allowing tighter flow control and reduced power consumption.

Subsonic Wind Tunnel

Low-speed tunnel operating at Mach numbers up to 0.3 for testing civilian aircraft, cars, and buildings.

Transonic Wind Tunnel

High-speed tunnel covering Mach 0.3–1.4 to study flow near the speed of sound where compressibility effects become significant.

Supersonic Wind Tunnel

Facility operating at Mach 1.4–5.0 for testing aircraft and missiles in supersonic regimes.

Hypersonic Wind Tunnel

Tunnel producing flow above Mach 5 to examine extreme heating, shockwave behavior, and re-entry vehicles.

Computational Fluid Dynamics (CFD)

Numerical method that solves the Navier-Stokes equations on computers to simulate airflow over full-scale models under varied conditions.

Drag and Lift Optimization

Design process that modifies shapes (wings, fuselage) to reduce drag and increase lift, improving fuel efficiency.

Stability & Control Surface Evaluation

Wind-tunnel or CFD assessment of rudders, ailerons, elevators, and other surfaces to ensure balanced, responsive flight control.

Hypersonic Flow

Airflow at speeds greater than Mach 5, characterized by intense shockwaves and high thermal loads.

Shockwave Interaction

Complex behavior of shockwaves as they form and impinge on vehicle surfaces, critical for spacecraft re-entry design.

By-Pass/Duct Design

Engineering of internal or external ducts that manage airflow across wide Mach ranges to maintain engine stability and prevent inlet unstart.

Turbine Blade Optimization

Application of aerodynamic and structural principles to shape wind-turbine or engine blades for maximal energy capture and minimal stress.

Inlet Design

Shaping of engine intakes to ensure smooth, stable airflow, preventing compressor stall or surge (e.g., F-16 or F-35 inlets).

Structural Wind Load

Forces exerted by wind on buildings or infrastructure that must be quantified to ensure safety and resilience.

Wind-Induced Vibration

Oscillations (flutter, sway) in tall or flexible structures caused by wind, addressed through aerodynamic damping or tuning.

Pedestrian Wind Comfort

Assessment of wind conditions at street level to improve safety, ventilation, and thermal comfort in urban design.

Sustainable Wind-Resilient Infrastructure

Buildings and systems designed with wind analysis to withstand extreme weather while supporting climate adaptation.

Alan Garnett Davenport

Pioneer of wind engineering renowned for developing modern wind-loading analysis methods and establishing boundary-layer wind tunnels.

Whirling Arm Device

Early 1746 apparatus by Benjamin Robins that rotated models through still air to study aerodynamic forces before wind tunnels existed.

First Enclosed Wind Tunnel

1871 facility constructed by Francis Herbert Wenham, providing a controlled airflow chamber for precise aerodynamic testing.