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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 ?
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
