Piston Engines
Piston Engines
Piston Engines
Using the altimeter in the cockpit how can we measure "pressure altitude"?
A rich mixture in terms of piston engine fuel system supply to the induction manifold is a mixture of air to fuel.
For maximum endurance the mixture control should be set to:
What is the best method for limiting the effects of vapour locking?
The purpose of the accelerator pump is?
In an aircraft equipped with a float type carburettor and a constant speed propeller, carburettor icing would probably first be detected by
How is a stable idle achieved in the carburettor?
The octane rating of a fuel characterises the :
For piston engines, mixture ratio is the ratio between the :
Which power settings are most likely to promote detonation in petrol engines?
Which statement is correct regarding fuel energy density?
What effect does the mixture fuel-air have on the flame front velocity
On a climb the decrease in pressure causes ....
When the carburettor air intake is in "Hot Air" the power output of the engine is reduced because:
What is the normal indication that a petrol engine is suffering from "Detonation"?
When would a pilot most likely expect carburettor icing?
Tetra ethyl lead is added to some aviation gasoline fuels to:
The colour of Aviation gasoline 100 LL is:
What is the purpose of the priming pump?
What is the purpose of power enrichment in a carburettor?
2 Groups of engines
1. Piston engines 2. gas turbine engines systems
Piston engines 2 arten
a) Unboosted/ Normal aspirated engine b)boosted
Unboosted/ Normal aspirated piston engine
the ambient air is drawn into the cylinder by the piston
boosted piston engines
a charger delivers compressed ambient air (more air mass) into the cylinder
Turboprop
gas turbine driving a propeller to create the thrust force
Turbofan
gas turbine driving a fan that creates thrust force as the reaction force to the acceleration of the air in the nozzle
Grundprinzip Piston engine
The high pressure inside the cylinder during combustion creates a force on typ of the piston, which is transmitted to the crankshaft, creating torque.
Was kann bei inverted cylinders passierenN z.B. beim Sternenmotor
Es entsteht ein Hydraulicing (oil flood) => Oil flows down into the cylinder head and blocks the movement of the piston. This oil must be drained (Säubern) from the cylinder by removing the spark plug before engine start
Welche Piston engines kommen am häufigsten in Airplanes vor?
Horizontal opposed air-colled engines ==> Boxer => 4-6 cylinder
Sternenmotor
Kurbelwellen in der Mitte => Ungerade Anzahl Zylinder ( bei 2-Reihiger Motor = gerade Zylinderanzahl) => Daraus ergibt sich die Zündreihenfolge
Verschiedene Arten Otto-Motoren
a) Reihenmotor b) V-Motor (Nockenwelle entscheidet, ob schneller oder langsamer Motor) c) Boxermotor (jeder Zylinder hat 2 Kerzen
vgl Bild
1) Zylinder 2) Kurbelwelle (Crankshaft) 3. Kurbelgehäuse (Crankcase) 4. Heat exchange
vgl. Bild
1. Vc (Clearance Volume) 2. TDC Top dead centre 3. bottom dead centre 23. Distance: length of stroke 4. Piston 5. Connecting Rod 6. connecting rod force 7. Crankshaft
Torque
F Rod * Arm F Rod= Connecting rod force
V Total im Zylinder
Vc + Vs = Vt Vc = Clearance Volume = Between TDC and the top of cylinder Vs = displacement between TOD and BDC
Compression ratio
\(Compression ratio = {Vs + Vc \over Vc}\)
Stroke
Distanve between TDC and BDC
Long Stroke engine where teh sroke is greater than the piston Bore (Zylinderbohrung) führt zu ?
Kraft mal Arm ist hier grösser => Grösser Tork
Short Stroke Engine where the stroke is less than the piston bore ist der Fall, wo?
Bei Rennmaschinen
3 factor for the power output of a single cylinder engine
1. Weight of air mixture taken in (Wie viel Gemisch) 2. Amount of compression 3. Number of working/power strokes per Minute = Drehzah
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Cartes-fiches
The magneto of an engine fitted with a constant speed propeller should be checked:
As engine speed increases in a low powered engine the ignition spark:
An important factor of the dual ignition system on an aircraft engine is to achieve ...
A six cylinder engine fires in which order ?
In an air-cooled aero-engine, cooling air is directed around the cylinders:
Maximum air flow past the cylinder cooling fins is effected by:
The automatic mixture control capsules are sensitive to:
Before starting why is it important to record the "static boost" ?
On a turbo-chared engine,what does the term "turbo-lag" mean?
The normal tendency of a propeller blade when it rotates is:
What is the main purpose of the intercooler ?
Why should the engine be turned over by hand prior to starting?
Absolute Pressure is always stated as:
EGT on a piston engine is used...
The gear booster pump of the CSU is for the purpose of:
Which statement is correct, when pushing the propeller lever forward will?
Running an engine fitted with a fixed pitch propeller at full throttle with the aircraft stationary and nose into strong wind will result in:
What is the reason for avoiding excessive ground idling?
On a single acting constant speed propeller what counter acts the centrifugal latches?
When is a carburettor fire most likely to occur?
What is the purpose of a supercharger ?
The aircraft is turned into wind prior to engine start to give ?
The turbocharger rpm is directly controlled by the:
What are the main problems associated with engine starting in extremely cold weather.
An electrical feathering pump is used to:
What is the correct procedure for setting take off power ?
When feathering a single acting constant speed propeller, Which force/s move the blades to feather?
When can we say that the aircraft is at critical altitude?
Counterweights are used to
The control system of a turbocharger tries to maintain a constant:
Using the cockpit instruments how would the pilot know that the engine has exceeded the “rated altitude”?
A constant-speed propeller ...
Why is a high pressure pump necessary with a diesel powered engine?
There is no fuel "jet" in a fuel injection system. Which component replaces the "jet"?
On a fuel injected engine which meteorological conditions are most likely to result in ?induction? icing?
What is the main advantage of a multi point injection system compared to a single point system?
Select the statement that is correct?
If engine speed is increased, the pressure in the carburettor choke will:
Which cockpit control operates both valves ?air? and ?fuel? together in a fuel injection system?
How is mixture adjusted on a diesel engine?
