Séance du mercredi - Education

CDIAS 34 Séance du mercredi

27 janvier 2021

1 – Météorologie et aérologie

2– Aérodynamique, aérostatique et principes du vol / 2.1– La sustentation et l'aile

3 Étude des aéronefs et des engins spatiaux / 3.2 – Les groupes motopropulseurs

ANGLAIS

• Comment vole un avion ?

• Comment fonctionne les moteurs ? a) différents types de moteurs

b) moteur à pistons

c) la réaction qu’est-ce que c’est ?

d) le turboréacteur à double flux

e) le turbopropulseur

• Existe-t-il des différences entre les nuages ?

(drag)

Comment vole un avion ?

https://www.youtube.com/watch?v=_rQAUHSTJIQ

Comment fonctionne les moteurs ?

ACTION / REACTION Squid

https://www.youtube.com/w

atch?v=NeM8f1yQWi8

Comment fonctionne les moteurs ?

TURBOJET ENGINE

Comment fonctionne les moteurs ? BY-PASS / 2 SPOOL

JET ENGINE

https://www.youtube.c

om/watch?v=KjiUUJd

PGX0

• Fan = soufflante

• Low pressure compressor = compresseur

basse pression (3 stages) runs at a lower

speed

• High pressure comprsessor = compresseur

haute pression (7 stages) runs at high speed

• Combustion chamber = chambre de

combustion

• Turbine (high and low pressure) = turbine

• Nozzle = tuyére

• BY PASS = double flux

• 2 SPOOL = double corps

TURBOPROP ENGINE

• Propeller = hélice ( 2, 3, 4 …..blades = pales )

• Gearbox = réducteur

• Shaft = arbre

• Exhaust = échappement

https://www.youtube.co

m/watch?v=teICr3Yg1

4U

TURBOPROP ENGINE

• Propeller = hélice ( 2, 3, 4 …..blades = pales )

• Gearbox = réducteur

• Shaft = arbre

• Exhaust = échappement

FOUR STROKE ENGINE

• Intake = admission

• Exhaust = échappement

• Camshaft = arbre à cames

• Valve = soupape

• Spark plug = bougie d’allumage (spark = étincelle)

• Piston = piston

• Connecting rod or piston rod = bielle

• Cylinder = cylindre

• Crankshaft = villebrekin

• Engine block = block moteur

• Timing belt = courroie de distribution

FOUR STROKE ENGINE

https://www.youtube.com/

watch?v=OGj8OneMjek

How a four stroke engine works

Let’s take a look at the basic internal parts of an engine.

Inside the engine block there is a crankshaft.

Piston rods are attached to the crankshaft.

Pistons are attached to the piston rods.

As the crankshaft turns, it causes the lifter to make each piston move up and down.

At the top of the crankshaft there is a camshaft which is connected to the

crankshaft by a timing belt.

While the crankshaft is making the pistons move up and down, the camshaft is

turning making the the valves to open and close.

FOUR STROKE ENGINE

Let’s take a look on how the combustion creates piston’s motion.

1st INTAKE STROKE

the inlet valve is opened and the fuel/air mixture is drawn in as the piston travels

down

2nd COMPRESSION STROKE

the inlet valve is closed and the piston travels back up the cylinder compressing the

fuel/air mixture. Just before the piston reaches the top of its compression stroke, a

spark plug emits a spark to combust the fuel air mixture.

3rd COMBUSTION STROKE

the piston is now forced down by the pressure wave of the combustion of the

fuel/air mixture. The engine’s power is derived from this cycle.

4th EXHAUST STROKE

the exhaust valve is opened and the piston travels back up expelling the exhaust

gases through the exhaust valve. At the top of this stroke the exhaust valve is closed.

FOUR STROKE ENGINE

This process is repeated .

What has been presented is the cycle of operation of one cylinder of a four stroke

engine. Generally engines have 2 or more cylinders acting in concert with each other

to produce the engine power.

fuel/air mixture = mélange air /carburant

to reach = atteindre

to emit = émettre

power = puissance

is derived = provient de

to expel = expulser

FOUR STROKE ENGINE

Existe-t-il des différences entre les nuages ?

https://www.youtube.co

m/watch?v=748DeQik0

d0

CLOUDS

Clouds are formed from minute* particles of water or ice held in suspension : their

effect on navigation and especially* on visual flight is significant* . Although* there is

infinite variation* in the shape and colour of clouds , certain general characteristics

can be identified to allow* us to describe several types.

The first major differentiation between clouds depends upon whether* they form in

a stable or unstable atmosphere. A stable atmospere will lead to stratiform or layer

clouds. An unstable atmosphere will lead to the formation of cumuliform or heaped

clouds often caracterised by vetical development.

Existe-t-il des différences entre les nuages ?

Clouds are further* classified according to the level of their base.

High level clouds have a a base above 20,000 feet above mean sea level*. At this

height the atmosphere is cold and these clouds will be composed of ice crystals

rather than* liquid water. The prefix CIRRO is used to denote high level.

Middle level clouds are prefixed by the word ALTO and have a base above 6,500

feet.

This initial division is known as the cloud family, whether it is high, medium or low

level cloud.

Let’s examine the main types of cloud. Starting with the high level clouds first. The

following definitions are taken from ‘The International Cloud Atlas Organisation'

High level clouds

CIRRUS which are abbreviated in forecasts* and reports* “CI" "Charlie India".

These are detached clouds in the form of white, delicate filaments, white patches,

and narrow bands. They have a fibrus* or silky* appearance.

CIRROCUMULUS : "CC" "Charlie Charlie", are a thin white patch or layer* of

cloud composed of small elements in the form of grains or ripples*, merged* or

separated but, more or less, regularly arranged*.

CIRROSTRATUS : “CS” "Charlie Sierra" is a transparent whitish* veil* of cloud

having a fibrous or smooth appearance*. This type of cloud will produce a halo around

the sun or moon.

Medium level clouds.

Moving now to the medium level clouds we have:

ALTOCUMULUS “A C" "Alpha Charlie" they are a white or grey patch*, sheet* or

layer* with shading* composed of rounded masses or roll; normallythese

elements are regularly arranged.

ALTOSTRATUS : “A S” "Alpha Sierra" is a greyish* or bluish* cloud sheet of

layer of striated, fibrous or uniform appearance, parts may be thin enough* to

vaguely reveal* the sun as through ground glass*

Low level clouds

We will now take a look at low level clouds: remember these are clouds having a

base below 6,500 feet. Note that this category also incudes* clouds of great vertical

extend*

STRATUS : "ST" "Sierra Tango", is generally a grey layer of cloud with a fairly

uniform base. Stratus cloud usually contains only relatively small vertical air currents

so cannot support* large water droplets*. This type of cloud can give drizzle* or snow

grains* mith a low enough temperature.

STRATOCUMULUS : “SC" "Sierra Charlie" clouds form a grey or or whitish patch,

sheet or layer of rounded masses or rolls.

Now for the clouds of great vertical extend,

which are classed as low level clouds because although

they are deep their base is below 6,500 feet.

NIMBOSTRATUS: “NS” “November Sierra” . NIMBUS meaning rain bearing*

and STRATUS meaning layer, is a great cloud layer , often dark., the base of which is

rendered diffuse by more or less constant rain or snow. It is thick enough* to blot

out*the sun.

CUMULUS : “CU » « Charlie Uniform » are detached clouds, generally dense

with sharp outlines, developing vertically in the form of rising mounds, domes or

towers, the bulging upper part of which resembles a cauliflower*.Sunlit parts of a

cumulus will be brilliant white while the base will be relatively dark and nearly

horizontal.

CUMULONIMBUS : “CB” “Charlie Bravo » is a dense, heavy cloud with

considerable vertical extend* forming moutains or huge towers. The upper part may

spread out* to form an anvil* wile the base is very dark. Lightning*, thunder* and

hail*are caracteristics of a CB . Cumulonimbu are a big hazard* to aviation.

• Minute = minuscule

• Especially = en particulier

• Although = bien que

• Variation = variété

• To allow us = nous permettre

• Whether = selon que (à ne pas

confondre avec weather = climat/

temps)

• Further = ensuite

• Mean sea level = niveau moyen de la

mer

• Rather than = plutôt que

• Forecasts = prévisions ( weather

forecasts )

• Reports = bulletins

• Fibrus and silky = filandreux et

soyeux

• Layer = couche

• Ripples = rides

• Merged = fusionné

• Regularly aranged = agencé de

façon ordonné

• Whitish veil = un voile blanchâtre

• Smooth appearance = d'aspect lisse

• Patch = nappe

• Sheet = voile

• Greyish = grisâtre

Vocabulaire:

• Bluish = bleuâtre

• Thin enough = assez mince

• Reveal = laisser apparaître

• Vertical extend = developpement verticale

• Support = contenir

• Large water dropelets = de grosses gouttelettes d’eau

• Drizzle = crachin / bruine

• Snow grains = poudreuse

• Rain bearing = porteur de pluie

• Cauliflower = choux-fleur

• To sread out = s'étendre

• An anvil = une enclume

• Lightning = éclair

• Thunder = tonnerre

• Hail = la grèle

• Hazard = danger / risque

Vocabulaire:

https://www.youtube.com/wat

ch?v=FMagDRCpJ14&featur

e=emb_logo

Exercices

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

BIA 2020

Contact : Patrick Le BERRE

marie.dobel@orange.fr