AMT 124 PISTON ENGINES Flashcards
without a powerplant, the ________ was never
developed.
Aerial screw
By placing further rows of cylinders behind the first produced ______ and ______
Double and Triple Bank radials
These engines, although very powerful, had the disadvantage of being heavy and presenting a large frontal area as they were air - cooled
Radial Engine
Barber’s engine was neither _____
nor _____.
efficient nor practical
These pistons are arranged
radially around a single crank. Although drag was increased the engines were light, rigid and produced high power.
_____ engines always have an odd number of cylinders.
Radial Engine
It is defined as the linear distance that the piton moves in the cylinder
Stroke
the first patent for heat engine was taken out in _____ by
JOHN BARBER
1791
Early aircraft used _____
engines. These have their cylinders arranged in a straight line,
one after the other, they can be liquid or
air cooled.
In-Line
The TDC is defined as when?
The piston is at the top of the stroke
The next major breakthrough in piston engine development came in
____ when Dr. August Otto developed the FOUR – STROKE,
FIVE – EVENT CYCLE.
1876
This engine always has odd number of cylinders
RADIAL ENGINE
Many in-line engines are ______, so that the
crankshaft is at the top and pistons below.
Inverted
Four stroke- Five event cycle is also known as?
Otto cycle
gave a large frontal area to the aircraft, but was short in length.
Radial Engine
The BDC is defined when?
The piston is at the bottom of the stroke
These engines powered the
fighter aircraft of World War 2. Liquid cooled, the ____
arrangement of cylinders could easily be streamlined into the
fuselage so reducing drag.
V engines
This arrangement makes a short rigid engine which is easily streamlines.
FLAT/HORIZONTALLY OPPOSED
The first patent for heat engine was taken out in 1791 by ____ and was neither efficient nor practical
John Barber
Exhaust Back Pressure happens at what stroke?
4th
The propeller is
driven from the _______ and this arrangement gave greater
ground clearance for the propeller.
crankshaft
The crankshaft rotates at ___ degrees as the piston moves from TDC to BDC
180
In the 3rd Stroke, volume is unchanged due to?
Piston’s stationary position at TDC
He built the first piston Engine which employed a battery ignition system and used a natural gas for fuel operated industrial machinery as lathers.
Etienne Leinor (1860)
which force is directly related to the production of the aircraft’s acceleration?
Thrust
When the piston is at TDC and at the end of the compression stroke:
Combustion takes place
IF the crank - throw measures 5 inches, the stroke measurement is?
10
Developed the four - Stroke, five - event cycle.
Dr. August Otto
The drag which is present when the aircraft continues to climb is known as?
The undesirable but unavoidable bi - product of lift
What could be the probable result of an exhaust back pressure?
The pressure in the cylinder increases slightly which causes the temperature to rise also
Was used for larger more powerful engines of eight to twelve cylinders
V ENGINE
What do you call the internal diameter of the cylinder?
Bore
Constant volume happens in the system when;
Combustion takes place
These have cylinders arranged in a straight line, one after the other, they can be liquid or air cooled.
INLINE ENGINE
In 1483, Leonardo Da Vinci conceived a flying machine he called as?
Aerial screw
which force is the resultant of the initial action force according to the coanda effect theory?
Lift
What is the piston movement when both valves are closed and the cylinder volume is decreasing?
Piston is moving up
An engine which has a bore equal to the stroke is known as ______
Over-square
The complete cycle taking _____ (4 x 180)
720 degrees
The inlet valve is open, permitting flow from atmosphere, through the carburetor into the cylinder. The piston is moving down and the cylinder volume is increasing. The cylinder pressure is decreasing below ambient. The charge temperature is decreasing. The mass of the charge is increasing.
1st stroke (induction)
The _____ valve is now open to atmosphere. The piston moving up forces the exhaust gas past it to the atmosphere. The atmosphere provides a resistance to the flow of exhaust gas which is termed ‘EXHAUST BACK PRESSURE’. Because of this the pressure in the cylinder increases slightly which causes the temperature to rise also.
4th stroke (Exhaust)
The _____ is equal to Twice the Crankthrow.
Stroke
When the piston is at TDC at the end of the compression stroke an electrical spark is produced at the spark
plug, and ignites the fuel air mixture. It should be appreciated that this does not result in an explosion of the
mixture, but is a controlled burning. This event is called ______.
Combustion
The ______ is connected to a crankshaft.
Piston
_____ and ______ are related to degrees of crankshaft movement, and position in relation to TDC and BDC
Piston and Valve Positions
The Stroke is equal to ______
Twice the crankthrow
Most modern light aircraft use four or six cylinder engines arranged in the _______ configuration. This arrangement makes for a short rigid engine, which is easily streamlined.
Flat/Horizontally opposed
Both valves are still closed. The piston is stationary at the top of the stroke (TDC) the temperature of the charge is increasing rapidly during combustion. The VOLUME is unchanged due to the stationary piston, hence the internal combustion engine is known as a ‘CONSTANT VOLUME ENGINE’. Pressure increases rapidly with the temperature increase. The piston is forced down by the pressure increase. The cylinder volume is therefore increasing. This means that cylinder pressure is decreasing, and as a function of that, the temperature decreases.
3rd stroke (power)
In the otto cycle there are five events:
Induction, Compression, Combustion, Power, Exhaust
The combustion process takes place with the piston at TDC. The volume in the cylinder at that moment in time
is constant. Combustion is said to take place at _______.
constant volume
Both of the valves are closed trapping the induced mixture in the cylinder. The piston is moving up. The cylinder pressure is increasing. The temperature of the charge is increasing. The mass of the charge is now fixed.
2nd stroke (compression)
Types of Engine Layout
In-Line Engine, V engines, Radial engines, flat/horizontally opposed engines
Layers of the Atmosphere
Troposphere, Stratosphere, Ionosphere, Exosphere
Parts of the Otto Cycle
Induction, Compression, Combustion, Power, Exhaust.
Parameters of Atmosphere
Pressure, Density, Temperature
Different Theories of Lift/Flight
Bernoulli’s Principle, Newtons 3rd law of motion, Equal Transit theory, coanda effect theory
