Aerodynamics in Aircraft Design Flashcards
The environmetal challenege aims to significantly reduce which three products from aviation by 2050?
Carbon Dioxide
Noise
Nitrogen Oxides
What are the three major technology areas in aerodynamics?
Aircraft configuration - shape optimisation, winglets, HLD
Drag reduction - Laminar flow tech, turbulence control, vortex reduction
Seperation control - control surfaces, vortex generators
What type of evolutinary progress do we expect to see in the coming decades?
Movement towards a new fuselage design to increase efficiency and reduce noise. Eg, blended wing body, double bubble, interchanagable box.
What are the three stages of aircraft design?
Concept Design
Preliminary Design
Detailed Design
What are the requirements of effective CFD software in aircraft design?
Sufficient and known level of accuracy.
Acceptable computational costs
Quick turn around time
What are the characteristics of a succesful aircraft design?
Aerodynamically efficient
Adequete control inside flight envelope
Economical design and low maintenance cost
Fuel efficient, non polluting and as quiet as possible.
What are the steps to succesful aerodynamic wing design?
1) Specify design criteria
2) Validate analysis tools before drawing conclusion
3) Start with a known aerofoil
4) Iterate Design
What is the lift to drag ratio?
A measure of overall aerodynamic efficiency. Varies with velocity and altitude.
What does a higher Thrust/Weight ratio mean?
Greater acceleration, higher max speed.
More fuel, higher gross take off weight
What does Weight/Wing Area (Wing loading) affect?
Stall speed, Climb rate, Takeoff/landing distances.
What are the three control surfaces and what motion do they control?
Airlerons - Roll
Elevators - Pitch
Rudder - Yaw
What is the difference between static and dynamic stability?
Static stability refers to an aircraft’s tendancy to counter a disturbance.
Dynamic stability refers to how quickly the aircraft returns to trim after a disturbance.
What does it mean if an aircraft is in trim?
The sum of moments around the centre of gravity = ZERO
What does moving the centre of gravity aft do to stability
Decreases stability.
What are the conditions for steady level flight?
Thrust = Drag Lift = Weight
