Aerodynamics
"Future Aero Engineer! Aeronautical engineering - paglipad patungo sa kinabukasan. Aircraft design, aerodynamics, propulsion, flight mechanics!"
1. Four Forces of Flight โ๏ธ
All flight depends on balancing 4 fundamental forces. Master these para maging excellent pilot o engineer!
LIFT โ
Generated by wing pressure difference (Bernoulli's principle). Upward force supports aircraft weight. L = ยฝฯvยฒSยทCL
Increases with: higher speed, larger wing area, higher air density, higher angle of attack (until stall)
WEIGHT โ
Gravitational force (W = mg). Always acts downward. Includes aircraft + fuel + cargo + passengers
Cannot be eliminated, must be balanced by lift in flight
THRUST โ
Forward force from engine/propeller. Overcomes drag, accelerates aircraft, climbs
Jet: expansion of hot gases. Propeller: Newton's 3rd law (push air backward)
DRAG โ
Air resistance opposing motion (parasitic drag + induced drag). Always opposes thrust
D = ยฝฯvยฒSยทCD. Increases with speed (quadratic!). At cruise: Thrust โ Drag
Flight Equilibrium: Hover/Level flight: Lift = Weight, Thrust = Drag | Climb: Thrust > Drag | Descent: Drag > Thrust
2. Aerodynamic Principles ๐ฌ๏ธ
How wings work sa air - yan ang core ng lahat ng aviation!
| Principle | Description | Effect on Lift |
|---|---|---|
| Bernoulli's Principle | Fast-moving air has lower pressure than slow-moving air | Upper wing surface: faster air โ lower pressure โ lift! |
| Newton's 3rd Law | For every action, equal & opposite reaction | Wing deflects air downward โ air pushes wing upward (lift) |
| Boundary Layer | Thin layer of air stuck to wing surface (viscosity effect) | Smooth surface = lower friction drag. Rough = higher drag |
| Stall | Angle of attack too high (>~18ยฐ), boundary layer separates | Lift drops suddenly, drag increases dramatically - dangerous! |
3. Aircraft Structures ๐๏ธ
How aircraft are built - strong yet lightweight para sa efficiency!
4. Propulsion Systems โ๏ธ ๐
| Type | Mechanism | Best For |
|---|---|---|
| Piston Engine + Propeller | Reciprocating engine (like car), propeller converts rotation to thrust | Small aircraft, helicopters, low-speed flight. Efficient at low speeds |
| Jet Engine (Turbofan) | Compress air โ ignite fuel โ expand hot gas โ exhaust pushes backward | Commercial/military jets. Most efficient for high-speed (cruise ~Mach 0.85) |
| Turboprop | Jet engine drives propeller + exhaust thrust | Medium-size cargo/regional aircraft. Better efficiency than pure jet |
| Rocket Motor | Controlled explosion of fuel + oxidizer (works in vacuum!) | Space launch. Only propulsion that works outside atmosphere |
5. Flight Control Systems ๐ฎ
How pilots control aircraft motion - 3 axes of rotation:
ROLL (Longitudinal Axis)
Left/right rotation - wing up/down
Control: Ailerons (elevons on delta wings)
Left aileron down โ left wing down (relative lift difference)
PITCH (Lateral Axis)
Nose up/down rotation
Control: Elevators on horizontal tail
Elevator up โ tail down โ nose up (moment arm creates rotation)
YAW (Vertical Axis)
Left/right rotation - nose swings
Control: Rudder on vertical tail
Rudder left โ tail pushed right โ nose swings left
6. Flight Performance & Operations ๐
Key Performance Metrics
- Cruise Speed: Optimal speed for fuel efficiency. Commercial jets: Mach 0.80-0.85 (~490-520 knots)
- Service Ceiling: Maximum altitude achievable. Thin air = less lift, thinner air for engines
- Takeoff Distance: Runway length needed. Depends on weight, temperature, altitude, wind
- Landing Distance: Includes flare, rollout. Reverse thrust + spoilers + brakes used
- Range: How far on full fuel. Determined by fuel capacity & consumption rate
- Payload: Max cargo/passenger weight. Trade-off between fuel capacity and payload
7. Practice Questions ๐
Common Board Exam Questions
Q1: Explain the four forces of flight and their relationships in level flight.
A: Lift = Weight (vertical balance), Thrust = Drag (horizontal balance). If Lift > Weight: aircraft climbs. If Thrust > Drag: accelerates
Q2: What is Bernoulli's principle and how does it generate lift?
A: Fast-moving fluid has lower pressure. Wing upper surface: air flows faster โ lower pressure. Lower surface: slower air โ higher pressure. Pressure difference pushes wing upward
Q3: What happens during an aerodynamic stall?
A: At high angle of attack (>~18ยฐ), boundary layer separates from wing. Lift drops suddenly, drag increases. Plane loses altitude. Recovery: lower nose to decrease angle of attack
Q4: Differentiate between jet engines and turboprop engines.
A: Jet: all thrust from exhaust gases, efficient at high speeds (Mach 0.8+). Turboprop: most thrust from propeller, more efficient at lower speeds (~400 knots), uses less fuel
Q5: How do ailerons, elevators, and rudders control aircraft motion?
A: Ailerons control roll (differential lift on wings). Elevators control pitch (tail up/down creates moment). Rudder controls yaw (tail deflects sideways). All use moment arm and aerodynamic forces
Q6: What factors affect takeoff distance of an aircraft?
A: Weight (heavier = longer), temperature (hot air = thinner = longer), altitude (high altitude = thinner = longer), runway surface condition, headwind (reduces needed airspeed)
๐ฅ Aero Challenge ๐ฅ
Master aeronautics! Four forces, aerodynamic principles, propulsion systems, flight control, performance analysis!
Engineering the sky - design safer, faster, more efficient aircraft!
Test Your Knowledge! ๐ง
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