CFD Technology of flight.pdf

5/19/2018 CFD Technology of flight.pdf

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Technology of FlightTechnology of Flight

References:

R. G. Grant: Flight: 100 years of aviation (DK Publishing Inc., New York, 2002);

The Illustrated Guide to Aerodynamics, 2nd edition, HC Skip Smith, TAB Books,

McGraw Hill Inc., New York, 1992.

R. Wilkinson, Aircraft structures and systems, Addison Wesley Longman

Limited, 1996.

A. C. Kermode, revised by R. H. Barnard and D. R. Philpott, Mechanics of Flight,

10th edition, Addison Wesley Longman Limited, 1996.

Types of flying machinesTypes of flying machinesGliders

Microlights

and ultralightsFixed wingaircraft

Rotorcraft

(helicopters

and

gyroplanes(autogyros)

Photo:NASA

GlidersGliders

Hang gliding basic

equipment needed

glider and harness.

Control pilots

movements alter the

centre of gravity

Paragliding-more

portable, easy;

Paramotors (powered

paragliders) engine,propeller, paraglider

Reference: N. Whittall, The complete hang gliding guide,

A&C Black Publishers , 1984

Photo:www.start-flying.com MicrolightsMicrolights andand ultralightsultralightsVery light 1 or 2 seat

airplanes, usually

less stringent

licensing.

Flexwing and 3 axis

microlights

Photos: www.start-flying.com

GlidersGlidersHeavier than air

craft withoutengines

Gliding principles similar to glidinganimals

Common methods -

aero-tow, winchlaunching,

Photo: Wikipedia

Image: How stuff works

GlidingGliding--aircraftaircraftGimli glider incident, 1983 Boeing 767-200,flying from Montreal to Edmonton, run out of fuelat 12 km altitude and landed in Gimli industrialpark airport.

Air Transat Flight 236, 2001- run out of fuel

above Atlantic, landed in Azores.Hapag-Lloyd Flight 3378, 2000- Airbus A310-304, run out of fuel 20 km away from airport,landed 500 m short from the runway.

Jakarta incident, British Airways 009, 1982-Boeing 747-200, failure of all four engines due tovolcano ash, glided outside the ash cloud, andengines restarted.


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1909 Pigs can fly, Claude

Moore-Brabazon

HistoryHistory

1911, female flyers1912 plane takes off from warship

1918-quadruplane

1929

1933

Boeing 247

1933

1933

1936

1936

1945

1947

19481949

1949

1954 1954

1954

1977

1989

1989

D. Davies & M. W ines, Antique and Classic Airplanes, Osprey Publishing Limited, 1989.

B. Gunston,The worlds greatest airplanes,\Elsevier-Dutton Publishing.

Helicopters andHelicopters and autogyrosautogyros

1922, the first hoveringfor over one minute.

1923, autogyro

Modern autogyro, photo:Wikipedia


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HelicoptersHelicopters

S. Newman, The foundations of helicopter flight, Edward Arnold, 1994.

Common configuration: main

supporting rotor+single tail rotor

Photo: Kai Tak : the final decade / Robbie Shaw.

Shrewsbury, England : Airlife Publishing, 1997.

HelicoptersHelicopters--controlcontrol

Single main rotor/tail rotor

Vertical main rotor thrust

Longitudinal main rotor

tilt fore/aft

Lateral main rotor tilt

lateral

Pitch main rotor tilt

fore/aft

Roll main rotor tilt lateral

Yaw tail rotorthrust/engine torque

Twin main rotor (tandem)

Vertical main rotor thrusts(collective)

Longitudinal main rotorstilt fore/aft

Lateral main rotors tiltlateral

Pitch main rotor tilt

fore/aft; main rotor thrusts(differential)

Roll main rotor tilt lateral

Yaw differential mainrotor tilt


HelicoptersHelicopterstwin main rotorstwin main rotors

Tandem aligned inlongitudinal direction, oneon each end of fuselage

Side-by-side placedlaterally, on pilons

Coaxial rotors on sameaxle

Synchropter- two axlesclose together andinclined outwards

Compound addition ofextra propulsion


HelicoptersHelicopterstwin main rotorstwin main rotors


AirplanesAirplanes

Photo:NASA

AirplanesAirplanes

Photo: Kai Tak : the final decade / Robbie Shaw.Shrewsbury, England : Airlife Publishing, 1997.

Flying in Hong Kong:

http://www.hkaviationclub.com.hk/

Flying in remote areas:


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Human powered flightHuman powered flight

Light eagle,prototype

aircraft, 92pounds

Researchpurposes,dynamics oflow Reynoldsnumberaircraft,aeroelasticbehavior oflight aircraft

Photo: NASA

Human powered flightHuman powered flight

19771979

Solar powered flightSolar powered flightPathfinder solararrays on upper

wing surface, 8 kWppower

Pathfinder Plus 12.5 kWp

HeliosHelios

Helios prototype- solarremotely piloted aircraft

World altitude record forpropeller-driven aircraft

of almost 97,000 feet.

Photo: NASA

Propulsion systemsPropulsion systems

Propeller propulsionPiston engine

Turboprops

Jet propulsionTurbojet

Turbofan

References:

The Illustrated Guide to Aerodynamics, 2nd edition, HC Skip Smith, TAB Books,

McGraw Hill Inc., New York, 1992.

Aircraft Structures and Systems, R. Wilkinson, Addison Wesley Longman Limited, 1996.

Mechanics of Flight, A. C. Kermode, revised by R. H. Barnard & D. R. Philpott,

10th edition, Addison Wesley Longman Limited, 1996.

PropulsionPropulsion

Choice of power plant

Small private aircraft

Powered by reciprocating (piston) engine

Large commercial transport and military

aircrafts

Predominantly propelled by turbo-jet or turbo-fanengines

Intermediate size of civil aircraft

Gas-turbine driving a propeller


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Comparison between jet and propeller for

thrust productionAdvantage of propeller propulsion

Higher efficiency at lower speed

For a propeller and a jet engines produce the same

thrust

Jet-engined aircraft is transferring energy to theslipstream faster than propeller-engined aircraft

The difference in energy transfer rate becomes less

marked as the flight speed increases

Propulsion systemsPropulsion systemsPropeller propulsion

Each part of the blade has a cross-section

similar to airfoil

Thrust is produced since the differences in

pressure between the forward and the

rearward facing surfaces of the rotating

blades

Torque converted

to thrust

PropellersProduction of thrust by rotating blades

The propeller blade is set at a positive angle of attackrelative to the resultant velocity

The resultant force of which is produced can be

resolved into forward thrust and tangential resistance

components

Trailing vortex

The rotating blades produces the trailing vortices take the

form of helical trails

Blade twist

The inner part of the blade is describing a coarser helix

than the tip

If all sections of the blade are to meet the resultant

velocity at the same effective angle of attack, the

blade will need to be twisted, so that the geometricpitch angle is greater near the hub than at the tip

Propeller efficiencyPropeller efficiency

Depends on the ratio of rotation speed to

forward speed, the curve usually given for fixed

pitch

Low pitch propeller high performance for low

forward speed and high rpm.

Variable pitch enables optimal efficiency. To

enable easy operation, modern variable pitch

propellers operate at constant speed.

Number and shape of the blades also important.

Piston enginePiston engine

Older but more complex device compared to jet

engines

Low cost, high efficiency, still popular today

Internal combustion engine

Piston enginePiston engineValve opening into cylinder, downward stroke of the pistonstarts

Fuel-air mixture is drawn in (combined in a carburator), thepiston makes upward stroke compressing the gas, andthen spark is discharged by ignition system

The burning drives the piston down and provides power tothe crankshaft, and fourth stroke upward exhaustsremaining gas through the now opened exhaust valve.

First engines liquid-cooled since aircraft were too slow forair cooling. Problem solved first in rotary engine, and thennewer designs with increased airspeeds and adequatecooling fans.

Radial arrangement high power (lots of cylinders) butalso high drag, with invention of turboprops becameunnecessary and now horizontally opposed configurationis used in reciprocating engine powered small aircraft.


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Propulsion systemsPropulsion systems

Jet propulsion

Simple concept, but special alloys andmanufacturing processes needed to withstand

high temperatures

A gas-turbine propulsion device

Compressor

is used to increase the pressure (and temperature) of

the air at inlet

Advantages of jet propulsionThere is virtually no limit of speed at which can be operatedWorks well at high altitude

The ratio of power to weight can also be very high

Jet enginesRamjet

Nozzle-shaped device, air compressed by ram effect of movingthrough the air, fuel is injected and ignited and expanded gas exhaustsat high velocity

High thrust at high speeds; must be in motion at high speed to start,300 mph at sea level.

Used in some early missiles or helicopter rotor blade tips, not commonin conventional aircraft propulsion

Pulsejet

Shutter-like check valve synchronized with pulsed injection of fuel,check valve is then shut gas bursts out of the exhaust and ram effectforces the check vave open to repeat the cycle.

Also requires high speed to start, usually launched by means ofbooster rockets, used in V-1 buzz-bombs in WWII, not used inconventional aircraft propulsion

HistoryInvented in 1930s independently by Sir Frank Whittle and Hans van Ohain

First flight for Whittle engine in 1937, Ohains engine in 1939.

Originally designed for military aircraft, small intake for low drag -> highnoise levels, inefficient.

1940, report by Theodore von Karman, that he doubted that jet enginescould ever be applied to aircraft, while K. D. Woods, aircraft designprofessor, claimed that they can never be made cheap enough forcommercial flights.

Jet engineJet engineCombustion chamber

in which fuel is injected into the high-pressure air as a f ine spray,

and burned, thereby heating the air

As the temperature rises, each kg of hot air needs to occupy a

larger volume than it did when cold, it thus rushes out of theexhaust at a higher speed than at entry

The jet normally emerges at a pressure close to the ambientatmospheric value, but high velocity

Turbine

Extracts some of the energy available in the exhaust jet in order todrive the compressor

Problem with pure turbojet engine not very efficient.

Production of thrust by a jet engine

Output thrust is only a small proportion of the total thrust

produced internally, indicating that there are very largeinternal stresses

In flight, much of the thrust is come from the pressuredistribution in the intake duct system

The overall net thrust is partly related to the air flow

around the outside of the engine

External flow produces drag

Round the leading edge (rim) of the intake, the flow

speed is high, so the pressure is low, a significantforward thrust component is produced

The aerodynamic design of the intake, ducting and

engine nacelle is thus very important

Turbofan propulsion

Fan is a propeller with a large number of blades

Producing a large amount of thrust for a given disc

area,blades are close together, each blade strongly

affects the flow around its adjacent neighbors; good

for high speeds; the flow can be compressed

gradually, creating a smaller loss of energy

Ducted fanA fan or propeller is placed in a duct or shroud

Duct

A duct can provide a means of reducing the air

speed and increasing its pressure locally

A ducted fan can reduce the speed and increase the

pressure of the flow enters the duct

By-pass or turbo-fan

engines

By-passing some of the

compressed air around the

outside of the combustion

chamber and turbine can

increases the size of the low

pressure compressor stage

The efficiency can beimproved by increasing the

mass flow rate of air whilereducing the jet speed

Bypass ratio ratio of air

passing aroundthe engine to

that passing through theengine

Higher bypass ratio, higher

efficiency, but lower maximumthrust


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High by-pass ratio turbo-fans or fan-jets

A significant proportion of the overall thrust comes

form the pressure difference across the fan blades

Advantages

Increases the turbo-fan efficiency

Less noise is producedThe shroud suppress some of the noise from the fan

Low jet speed

-> turbo-fan engine can be extremely quiet

Disadvantage

Increases the diameter of the lowest pressure stage,

hence the fan diameter

the engine size increases

For large transatlantic aircraft

Four wing mounted and ducted engines must be used

for cruising at high subsonic Mach number

For twin-enginedt ransports and for cruise Mach numbersup to 0.86

Higher-efficiency unducted designs are preferable

Reheat or afterburning

Burning more fuel in an extended tailpipe sectionGives a significant boost in thrust

AdvantagesGives additional thrust with a relatively small increase inweight

High-efficiency for supersonic flight

DisadvantagesExtremely inefficient in low speed flight

Normally only used for takeoff

The extra pipe length produces extra drag when not inuse

Thrust reversal

Thrust reversers deflect the exhaust jet forward

and provide additional breaking action

Used for shorten the landing run for jet propulsion aircraftwith no propeller

Same effect in propeller engines with pitch reversal

Can be operated safely only on he ground, inhibited inflight.

Turbo-props

A propeller is driven by the gas-turbine

Designed for low flight speed

Higher efficiency than pure turbo-jet

Most of the energy available in the exhaust gases is extracted bythe turbine, and fed to the propeller

Gearbox to reduce rpm before attachment to the propeller

Nearly all thrust comes from the propeller (85-90%), rather thandirectly from the engine as jet propulsion

Propeller has higher propulsion efficiency than jet

Advantages

High power-to-weight ratio as turbo-jet propulsion

A power output that rises with flight speed

Disadvantages

When used with a conventional propeller, it is limited to

use at Mach numbers of less than about 0.7

Large heavy and complex gearboxBecause of the high rotational speed of the turbine,

turbo-props normally use a reduction gearbox toconnect the propeller shaft to that of the turbine

-> for large engines, the gearbox becomes a very large,

heavy and complex item, reducing some of the

theoretical advantages of the system

Supercharging and turbocharging

At high altitude, less parasite drag

due to lower air density, but engine

performance is also worse

Supercharger

Consist of centrifugal compressordriven from the crankshaft

Increases the power-to-weight ratio

By pressurizing the air beingfed into the cylinders, a larger

mass of air is used in each

working stroke

Advantages

Enables an engine to operate

at higher altitude than it couldin unsupercharged form

Enables an aircraft to take offheavily laden from high

altitude airfields on hot days


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Turbocharger

Similar to supercharger

The compressor is driven by turbine, which is poweredby the residue energy in the exhaust gases

Advantages

More efficient than a plain supercharger since it

makes use of wasted heat

Disadvantages

For small aircraft flying at low altitude

-> increases of cost and complication of the engine, the

pilot has to monitor or control the boost pressure

Performance comparisonsPerformance comparisons

Low speeds (


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Takeoff performanceTakeoff performance

VTOL vertical take-

off and landing; firstpatent in 1928 to

Nicola Tesla,

prototypes in 1950s

Directional thrust

Tiltrotor (example V-22

Osprey)

Directed jet thrust

(example Harrier II)

Landing performanceLanding performance

Landing distance depends on approach and

touchdown speed, rapidity of brakingBraking action depends on local conditions;

friction coefficients- dry concrete 0.7, light rain

0.5; heavy rain 0.3; snow or ice 0.1-0.2

Flaps increase drag but also increase lift; result-

slower touchdown speed

Also affected by wind, but not by touchdown

mas

Supersonic FlightSupersonic Flight

Supersonic flowAircraft designs are totally different in flight with highspeed and low speed

Different designs of engines, wing shapes and fuselagesMost aircraft have to land and take off and must thereforebe capable of satisfactory operation at both subsonic andsupersonic speed

Speed of sound

Sound transmission- pressure disturbances in the air.Same speed of transmission for disturbances createdby airplane flying.

Depends upon the absolute air temperatureAt low altitudes, where the temperature is relatively high, thespeed of sound is higher than it is at high altitudes where the

temperature is lower

High speed flow

The flow is undisturbed until it crosses the shockwave where speed is suddenly reduced, and airpressure temperature and density, suddenly increase

Shock wave

The along which the abrupt change in speed,temperature and pressure take place

Mach numberFlight Mach number = aircraft speed

speed of sound

M 1 (supersonic flight)

Subsonic patch appears near thenose of the aircraft

Flow speed decreases andtemperature increases beyondthe shock wave near the nose,the increasing of temperaturealso increasing the sound ofspeed

Local Mach number

Change in density

The density of air reduces as the speed is increased in the large

pressure differences region

Compressible flow -> the density of the flow can be changed

Compressible flow becomes significant when Mach number is larger

than one

Strength of shock wave depends on the normal component

of the oncoming flow velocity which is perpendicular to the

shock wave curveStronger the shock wave, greater the change of velocity, pressure

and density


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Drag in supersonic flightDrag in supersonic flight Some aircraft characteristicsSome aircraft characteristics

Swept wings smaller component of forwardvelocity relevant to wings airfoil; lowerperformance at low speeds; improved lateralstability

Sharp leading edges ideal for supersonic flight,but have poor low-speed performance

Control problems vortex generators used, withconventional control surfaces shock waves canform at junction between fixed and movableparts.

Propulsion for Supersonic FlightPropulsion for Supersonic Flight

Intake designTurbo-jet and turbo-fan designs do not acceptsupersonic flow at inlet

By placing the engine in a suitably-shaped duct, itis possible to slow the air down to subsonic speedsbefore entry

The duct is designed for compressing the flow through aseries of oblique shock waves, a region of shocklesscompression and a weak normal shock

Part of the compression is provided by the shock waveproduced by the wing, this shows the importance ofintegrating the design of the engine intake with that of the

wing

Exhaust nozzle

Variable geometry nozzle is required for

supersonic aircrafts

Variable geometry nozzle can be adjusted to

produce a convergent-divergent configuration for

high-speed flight

In a convergent-divergent nozzle, the jet can beaccelerated to Mach numbers greater than 1

For subsonic aircraft the jet is normally accelerated by

means of a simple fixed converging nozzle, the jet

maximum Mach number can be obtained is 1

Supersonic aircraft invariably use reheat, which also

requires the use of a variable geometry nozzle

The designs involving a large number of moving

parts, all of which have to stand up to very high

temperatures

The complexity of the nozzle mechanism may be

reduced if a two-dimensional design is usedinstead of the conventional axi-symmetricarrangement

The variable-geometry slot can be arranged

to produce thrust vectoring for control

purposes, and short take-off and landing(STOL)

Ramjet propulsionThe simplest form of jet-propulsion

Only consist of a suitably shaped duct with acombustion chamber

When air enters the intake of a jet engine, its

speed is reduced, and the pressure risescorrespondingly

Ram compression effect means that as the aircraftspeed rises, the compressor become less and lessnecessary

At Mach number in excess of about 3, efficient propulsioncan be obtained with no compressor at all

Elimination of the compressor means that the turbineis also unnecessary


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The thrust force is produced mainly by a high

pressure acting on the interior walls of theintake

For efficient operation at high Mach numbers, a

more complicated intake geometry is required,

which is similar to the types used for thesupersonic turbo-jet propulsion

Scramjet propulsion

Operate at very high Mach numbers

Supersonic flow in the combustion chamber

Reactive chemicals or gases must be used as its fuels

Advantage

Eliminated the energy degradation in the turbine andcompressor resulting in high efficiency at high Mach numbers

Kinetic heating effects in such a high speed render

conventional aluminium alloys and construction

techniques unsuitable

Disadvantage

Inefficient below a Mach number of about 3

Other form of propulsion is required to provide the initial

acceleration to high speed

Initial booster rocket is normally used in missiles

Flight-launched from a mother aircraft is required for

ramjet-propelled aircrafts

Dual-mode turbo-ramjet

Use a turbo-jet engine inside a ramjet duct

At low speed

The engine performs as a conventional turbo-jet

At high Mach numbers

Some or all of the air may be by-passed around

the main core engine and used in an afterburner toproduce ramjet propulsion

Take-off or landing require a reasonable

subsonic performance

The wing with acceptable low speed and high

speed performance and which does not have any

violent change in flow characteristics as the aircraft

accelerates through its speed range should beemployed

Supersonic flight- mainly military aircraft

Civil supersonic aircraft Concorde no longer

in service

The ConcordeThe ConcordeUK and France startedworking separately in1956, jointly in 1962.

First flight in 1969, Mach2 achieved in 1970.

Tupolev Tu-144 the firstflight two months before

Concorde, but neverentered commercialservice. Crashed in 1973Paris airshow.

P. R. March, The Concorde Story, Sutton

Publishing Limited, 2005.

The ConcordeThe ConcordeOnly supersonic passengeraircraft

New York-London flight typically 3-3.5 hours. Record:2 h 55 min 15 s.

Droop-nose for visibilityduring take-off and landing.

Commercial flights 1976

(BA London-Bahrain, AirFrance Paris-Rio deJaneiro.

Total of 20 Concordes werebuilt.




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The ConcordeThe ConcordeAccident in 2000, crash ontake-off in Paris

Flights resumed in 2001 afterupgrades and recertification.

Last flight Oct. 2003.Commercial reasons, notechnical support from Airbus,successor of joint Anglo-French manufacturers.



The ConcordeThe ConcordeRange 6880 km

Fuel consumption 25629 l/h

Cruising speed Mach 2

Fuselage width 2.5 m

108 passengers

2 pilots, one flight engineer, 8cabin crew

Flew around the world in 29h59 min.

Tupolev Tu-144LL flyinglaboratory, joint research byNASA and Russianaerospace industries, 1996-1999.

Development of USA-builtsupersonic jetliner currentlyon hold.



Aircraft ShapesAircraft Shapes

Aircraft shapes

The overall shape of the aircraft strongly

depends on its purpose

Required cruising speed and altitude

Required stability and maneuverability

Required capacity

Aircraft partsAircraft partsThe mainplane or wing

Most important part, generates lift. Can also carry fuel, supportundercariage or weapons loads.

Flying wing only for some special purpose aircraft, remotecontrol aircraft, B2 bomber; low radar cross-section

The fuselage or bodyForms the body, housing the crew, payload, aircraft systems,forms structural link between wing and tail unit. May carry theengines, and typically has environmental control, pressurizedenvironment (2.4 km for civil, 7.6 km for military) whichgenerates tensile loads.

The tail unit (foreplanes for canard-type)Typically vertical fin with a movable rudder and horizontaltailplane with movable elevators, or an all-moving horizontaltailplane. Canard-type horizontal tail surface replaced orsupplemented with a moving control surface at the nose.

Mountings for other systems (undercarriage, engines,etc.)

Aircraft partsAircraft parts

Aircraft ShapesAircraft Shapes

R. Wilkinson, Aircraft Structures and Systems, Addison Wesley Longman Limited, 1996


13/14

WingsWings

Biplanes

Monoplanes

Most of modern aircraft, needs stiff, strong wing, butlower drag is obtained

Braced monoplanes diagonal bracing strut betweenthe wing and fuselage, lighter structure of the wingbut extra drag.

Cantilever wing (at different positions)Low wing (jet transport, light aircraft)

High-wing (turbo-prop transport)

Low-wing or mid-wing (combat aircraft)

Speed : high speed, smaller wing span, low wingarea, high wing loading.

WingWing planformplanform

Elliptical ideal shape, the lowest drag,

expensiveTapered similar aerodynamics toelliptical

Rectangular- most economical, butheavier than necessary.

Combination of rectangular and taperedplanform.

Wingtip shapeWingtip shape

effectseffects

Tip shape affects tip

vortex induced drag

Drooped wingtip

Upswept wingtip

Hoerner wingtip

WingletsWingletsIncreased effective aspect ratioCreates lift perpendicular to theairstream

As a result, there is a forwardcomponent, negative drag orthrust

However, increases parasitedrag and interference drag

Effective where vortex action isstrong, i.e. low speeds or highaltitudes, also in STOL aircraft

Can also be used on propellertips, resulting in higher efficiencydue to lower propeller drag

SweepSweep--back, swing wings, delta wingsback, swing wings, delta wings

Swept wings reduce local Mach number, shiftaerodynamic centre closer to the centre of gravity.Problems reduced lift-to-drag ratio, increasedlikelihood of tip stalling

Swing wings changing sweep back in flight

Delta wings for fighter aircraft, high speed +ability fortight turns Swing wingsSwing wings


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Flaps, slats, spoilers, lift dumpersFlaps, slats, spoilers, lift dumpers

Flaps are fitted at trailing edges, reduce landingspeed by increasing lift and drag

Slats extend forward from the leading edge,increase the lift by increasing camber. Slot gapbetween the slat and leading edge, reducestendency to stall.

Spoilers on top surface of aircraft with goodglide and low speed performance, increase dragbut reduce lift.

Lift dumpers on top surface of larger aircraft,instant reduction of lift

TailTail

Purpose stability and control

Vertical fin+horizontal stabilizer

Twin fins+horizontal stabilizer smaller fins

T-tail horizontal surface near the top of the tail:improved spin recovery, also horizontal surfaceplaced outside downwash; problems: additionalweight, being immersed in the wake of stalledwing

V-tail single surface on either side of center linecanted upward; vertical projection provideslongitudinal stability, horizontal projectionprovides directional stability. Problem complicated control.

CanardsCanards

Advantage

additional lift, outside

downwash

Disadvantage-

destabilization at

large angle of attack

Aircraft designAircraft designConceptual design, preliminary design (mainly aerodynamic),

detail design (mainly structural)

Very complex, compromises necessary, depending on priority ofdesired design properties

Computer aided design

Aerodynamic testingAerodynamic testing

Wind tunnels

Force tests, pressure

tests, flow patterns

Flight testing

Some different designsSome different designs

Lear Fan prototype,

1981, entirely

graphite-epoxy

composite, terminateddevelopment when

funds exhausted

Beech starship, first

composite aircraft to

be certified

Documents

CFD Technology of flight.pdf