Air + PlaneAir + Plane

AST 406AST 406

ChallengeChallenge

To design and make a better airplane;To design and make a better airplane; To understand the atmosphere better;To understand the atmosphere better; To understand how air flows;To understand how air flows; To understand how weather affects air To understand how weather affects air

travel;travel;

Activity: Make a PlaneActivity: Make a Plane

Take a piece of paper and make an airplane Take a piece of paper and make an airplane that you think will fly the farthest;that you think will fly the farthest;

What makes a plane fly farther?What makes a plane fly farther? What makes a plane fly straighter?What makes a plane fly straighter? Suggest characteristics of a good paper Suggest characteristics of a good paper

airplaneairplane

Paper Airplane RubricPaper Airplane RubricPropertyProperty Desired Desired

DesignDesign Aerodynamic – delta shapeAerodynamic – delta shape

Control of air movement over wingsControl of air movement over wings

Helps plane move in desired directionHelps plane move in desired direction

Wing AreaWing Area MaximumMaximum

MassMass MinimalMinimal

Weight is balanced throughoutWeight is balanced throughout

MaterialMaterial Keeps shapeKeeps shape

LaunchLaunch Throw forward/up from centre of gravityThrow forward/up from centre of gravity

Atmosphere

The atmosphere is the layer of air The atmosphere is the layer of air surrounding the earth;surrounding the earth;

Air is the mixture of gases that make up the Air is the mixture of gases that make up the atmosphere;atmosphere;

Air is ~80% Nitrogen gas (NAir is ~80% Nitrogen gas (N2) and ~20% ) and ~20% oxygen (Ooxygen (O2).

There are also small amounts of water vapour (H2O), Carbon Dioxide (CO2), and Argon (Ar);

Atmospheric PressureAtmospheric Pressure

Air has mass;Air has mass; Atmospheric pressure is the weight, or force Atmospheric pressure is the weight, or force

down, of the air in the atmosphere;down, of the air in the atmosphere; The unit of pressure is the Pascal or Pa;The unit of pressure is the Pascal or Pa; 1 Pa = 1 Newton of Force on 1 m1 Pa = 1 Newton of Force on 1 m22;; Atmospheric pressure is about 101300 Pa Atmospheric pressure is about 101300 Pa

or 101.3 kPa (kiloPascal);or 101.3 kPa (kiloPascal);

High and Low PressureHigh and Low Pressure

Greater atmospheric pressure means that Greater atmospheric pressure means that there are more particles in a volume of air;there are more particles in a volume of air;

Less particles = less pressure;Less particles = less pressure; Warmer air rises, the particles move faster Warmer air rises, the particles move faster

and farther apart; thus it has a lower and farther apart; thus it has a lower pressure than cooler air;pressure than cooler air;

Air particles move from zones of high Air particles move from zones of high pressure (with lots of particles) to zones of pressure (with lots of particles) to zones of low pressure (fewer particles)low pressure (fewer particles)

Layers of Air

The atmosphere is a thin skin on the Earth;The atmosphere is a thin skin on the Earth; It is 500 km high;It is 500 km high; There are 5 layers:There are 5 layers:

– Troposphere: (0-15 km) - denseTroposphere: (0-15 km) - dense– Stratosphere: (15-50 km) – ozone layerStratosphere: (15-50 km) – ozone layer– Mesosphere: (50-80 km) - coldestMesosphere: (50-80 km) - coldest– Thermosphere: (80-500 km) – UV absorberThermosphere: (80-500 km) – UV absorber– Exosphere: (500 km +) – lowest densityExosphere: (500 km +) – lowest density

AirplanesAirplanes

By flying in the highest altitudes, planes fly By flying in the highest altitudes, planes fly through lower density air;through lower density air;

This results in lower friction or air This results in lower friction or air resistance; and greater speeds.resistance; and greater speeds.

This saves on fuel expenses;This saves on fuel expenses;

ActivityActivity

Air pressure demonstration with candle in Air pressure demonstration with candle in beaker beaker

Workbook, Page 117 – 118Workbook, Page 117 – 118

Air Circulation

Air masses move around because of the Air masses move around because of the different densities and temperatures of air different densities and temperatures of air masses around the world due to: masses around the world due to: – Location – above water/landLocation – above water/land– SeasonSeason– Time of dayTime of day– Rotation of the EarthRotation of the Earth

This causes patterns to emerge;This causes patterns to emerge; Air circulates in specific global movements;Air circulates in specific global movements;

ExampleExample

Air that has been warmed at the Equator becomes Air that has been warmed at the Equator becomes lighter and less dense;lighter and less dense;

It moves towards the North and South Poles;It moves towards the North and South Poles; Air that has been cooled at the Poles moves Air that has been cooled at the Poles moves

closer to the Earth’s surface and replaces the closer to the Earth’s surface and replaces the warmer air;warmer air;

These circulation loops are called cells;These circulation loops are called cells; Pilots use prevailing wind patterns to help them fly Pilots use prevailing wind patterns to help them fly

faster and use less fuel;faster and use less fuel;

Depression/Anti-CycloneDepression/Anti-Cyclone

Depression - DDepression - D– low air pressure - Llow air pressure - L– bad, rainy weatherbad, rainy weather

Anti-cyclone - AAnti-cyclone - A– high air pressure - Hhigh air pressure - H– sunny, drier weathersunny, drier weather

Hi/Lo PressureHi/Lo Pressure

A Mighty Wind Prevailing winds are major air currents that blow in Prevailing winds are major air currents that blow in

a given direction according to global patterns of a given direction according to global patterns of movement;movement;

An air mass is a large expanse of the atmosphere An air mass is a large expanse of the atmosphere with relatively uniform temperature and humidity with relatively uniform temperature and humidity (water content);(water content);

An anti-cyclone is an area of air circulation An anti-cyclone is an area of air circulation surrounding a high pressure centre.surrounding a high pressure centre.

A depression is an area of air circulation A depression is an area of air circulation surrounding a low pressure centre;surrounding a low pressure centre;

A cyclone is a tropical storm with violent winds A cyclone is a tropical storm with violent winds revolving around an area of low pressure;revolving around an area of low pressure;

Air CellsAir Cells Air that has been warmed at the Equator becomes Air that has been warmed at the Equator becomes

lighter and less dense;lighter and less dense; It moves towards the North and South Poles;It moves towards the North and South Poles; Air that has been cooled at the Poles moves Air that has been cooled at the Poles moves

closer to the Earth’s surface and replaces the closer to the Earth’s surface and replaces the warmer air;warmer air;

These circulation loops are called cells;These circulation loops are called cells;

A Mighty WindA Mighty Wind An air mass is a large expanse of the atmosphere An air mass is a large expanse of the atmosphere

with relatively uniform temperature and humidity with relatively uniform temperature and humidity (water content); (water content);

A depression is an area of air circulation A depression is an area of air circulation surrounding a low pressure centre;surrounding a low pressure centre;

A cycA cyclolone is a tropical storm with violent winds ne is a tropical storm with violent winds revolving around an area of revolving around an area of lolow pressure;w pressure;

An anti-cyclone is an area of air circulation An anti-cyclone is an area of air circulation surrounding a high pressure centre;surrounding a high pressure centre;

ActivityActivity

WorkbookWorkbook Page 121-122Page 121-122

ActivityActivity

Create an paper airplane with a air-foil shaped Create an paper airplane with a air-foil shaped wing or this one.wing or this one.

Use the heavier card stock;Use the heavier card stock; With our class rubric, re-design your plane;With our class rubric, re-design your plane; Each student will make a 3D drawing of your plane Each student will make a 3D drawing of your plane

with side, front and overhead views;with side, front and overhead views; Calculate the total area of wing space on your Calculate the total area of wing space on your

airplane;airplane; Determine the mass of the plane;Determine the mass of the plane; Calculate the wing area: mass ratio;Calculate the wing area: mass ratio;

Design a Better PlaneDesign a Better Plane

With our class Rubric, re-design your plane;With our class Rubric, re-design your plane; Calculate the total area of wing space on Calculate the total area of wing space on

your airplane;your airplane; Determine the mass of the plane;Determine the mass of the plane; Calculate the wing area: mass ratio;Calculate the wing area: mass ratio; Each student will make a 3D drawing of Each student will make a 3D drawing of

his/her plane with side, front and overhead his/her plane with side, front and overhead views;views;

Isometric and Orthographic ViewsIsometric and Orthographic Views

Isometric DrawingIsometric Drawing

EvaluationEvaluation Line Quality

5 Crisp, clear,

consistent lines (Object lines

stand out)

4 A f ew wavy lines, line

wavers off grid lines slightly

3 I nconsistent

lines, lines are wavy, pencil is

not sharp

2 Lines are not straight, did

not use a ruler or straight

edge Neatness 5

No smudge or eraser marks

4 One or two smudge or

eraser marks

3 Three or f our

smudge or eraser marks

2 More than 5 smudge or

eraser marks

Accuracy

5 Perf ect

dimensioned drawing, no mistakes

4 One or two dimensions

are off

3 Three or f our dimensions are

off

2 More than 5

dimensions are off

Title Block 5 Neat legible

handwriting, all inf ormation is

present

4 Handwriting is slightly messy or

missing one piece of

inf ormation

3 Handwriting is

messy or missing two pieces of

inf ormation

2 Handwriting is not legible or missing more than 3 items

Scale 5 Scale is stated, Page is fi lled, Scale a multiple of 2/ 5/ 10 Diagram follows scale

4 3 of the items

3 2 of the items

2 1 of the items

Issues in Atmosphere ResearchIssues in Atmosphere Research

Wind energyWind energy Smog Smog Thinning of the Ozone layerThinning of the Ozone layer Pollution of the atmospherePollution of the atmosphere Climate change/Global warmingClimate change/Global warming Greenhouse Gas EffectGreenhouse Gas Effect

Liquid AirLiquid Air

Air can be thought of as a liquid;Air can be thought of as a liquid; They both flow;They both flow; The greater the depth, the greater the The greater the depth, the greater the

pressurepressure Higher density = higher pressure and v.v.Higher density = higher pressure and v.v.

ActivityActivity

Workbook, page 123-124;Workbook, page 123-124; Textbook, page 233-239;Textbook, page 233-239; Balloon blow up!Balloon blow up!

GasGas

In a gas, the pressure depends on the In a gas, the pressure depends on the number of collisions between the gas number of collisions between the gas particles and the container;particles and the container;

The more collisions the greater the The more collisions the greater the pressure;pressure;

Air pressure is affected by:Air pressure is affected by:– The temperatureThe temperature– The volumeThe volume– The number of particlesThe number of particles

Pascal’s PrinciplePascal’s Principle

An increase in the pressure in an enclosed An increase in the pressure in an enclosed fluid is transmitted in all directions;fluid is transmitted in all directions;

E.g. the pressure of air in a car tire is the E.g. the pressure of air in a car tire is the same everywhere against the walls of the same everywhere against the walls of the tire;tire;

The brake system of a car uses Pascal’s The brake system of a car uses Pascal’s principle when the fluid is pushed from the principle when the fluid is pushed from the pedal to the brakes;pedal to the brakes;

PressurePressure

Pressure is a force applied over an area.Pressure is a force applied over an area. Pressure (Pascal) = Pressure (Pascal) = Force (Newtons)Force (Newtons) Area (mArea (m22)) P = P = FF AA

ExampleExample

What is the pressure of 50 Newtons of What is the pressure of 50 Newtons of Force applied over a 4 mForce applied over a 4 m2 2 area?area?

P = F/AP = F/A = 50 N/4 m= 50 N/4 m2 2

= 12.5 Pa= 12.5 Pa

So What is Force?So What is Force?

Force is a push or pull that can change the Force is a push or pull that can change the motion of an object;motion of an object;

It can:It can:– make move a stopped object;make move a stopped object;– slow down a moving object - deccelerateslow down a moving object - deccelerate– speed up a moving object - accelerate;speed up a moving object - accelerate;– it can change the direction of an object;it can change the direction of an object;– It can support an object;It can support an object;

Resultant ForceResultant Force

When you add two or more forces together, When you add two or more forces together, the overall force, or net force is called the the overall force, or net force is called the Resultant Force.Resultant Force.

Net Force =Net Force = 20N up 20N up

– – 20 N down20 N down

0 N 0 N

Force ArrowsForce Arrows

Forces can be represented by arrows;Forces can be represented by arrows; Forces can be added to each other to get Forces can be added to each other to get

the Resultant Force;the Resultant Force; = = 5N Left 5N Left

Bernouilli’s PrincipleBernouilli’s Principle

The higher the speed of a fluid, the lower the The higher the speed of a fluid, the lower the pressure and vice versa;pressure and vice versa;

Air particles that pass over an airplane wing Air particles that pass over an airplane wing have to move faster than air particles below have to move faster than air particles below the wing in order to avoid a vacuum;the wing in order to avoid a vacuum;

These faster air particles exert less pressure These faster air particles exert less pressure down compared to the pressure up ;down compared to the pressure up ;

This creates an overall upwards force or a This creates an overall upwards force or a Buoyant Force, FBuoyant Force, Fbb – or LIFT. – or LIFT.

Bernouilli Creates LiftBernouilli Creates Lift

Archimedes PrincipleArchimedes Principle

An object immersed in a fluid is subjected to An object immersed in a fluid is subjected to a buoyant (floating) force, Fa buoyant (floating) force, Fbb, EQUAL to the , EQUAL to the

weight of the fluid displaced by the object;weight of the fluid displaced by the object; The fluid can be air, so:The fluid can be air, so:

– An object floats UP if its weight is less than FAn object floats UP if its weight is less than Fbb

– An object remains at level if its weight =FAn object remains at level if its weight =Fbb

– An object sinks is its weight is more than FAn object sinks is its weight is more than Fbb

Archimedes Lifts UpArchimedes Lifts Up

The Big ExplanationThe Big Explanation

Airplanes fly because the shape of the wing Airplanes fly because the shape of the wing causes air to pass more quickly over the upper causes air to pass more quickly over the upper side of the wing(s); side of the wing(s);

The faster flowing air creates an area of lesser air The faster flowing air creates an area of lesser air pressure;pressure;

Since this is less than the normal air pressure, Since this is less than the normal air pressure, LIFT is created;LIFT is created;

This creates a Buoyant Force that lifts the plane This creates a Buoyant Force that lifts the plane up;up;

Various control mechanisms add stability to a Various control mechanisms add stability to a plane.plane.

ExampleExample

If an aeroplane is under an atmospheric If an aeroplane is under an atmospheric pressure of 100000 Pa, and its weight is pressure of 100000 Pa, and its weight is 1000000 N, what area of wing span does it 1000000 N, what area of wing span does it have?have?

Airplane DeviationsAirplane Deviations

Airplane ControlsAirplane Controls

ActivityActivity

Workbook: pages 45-46;Workbook: pages 45-46; Textbook: pages 79-87;Textbook: pages 79-87; Complex TasksComplex Tasks Boat raceBoat race Mouse Trap CarMouse Trap Car