Transcript intro.phys.psu.edu

How do engines work?
Can Ju(ckj5049),
Di Zhao(dfz5027),
Tian Dong(tpd5105)
1.Vehicle’s Power Source
The source of a vehicle is the engine, and
the engine’s power is delivered from the
internal cylinder. An engine cylinder is the
place where inner energy of the fuel is turned
into kinetic energy.
1.Vehicle’s Power Source
It works like this: fuel burns in the cylinder,
which creates a huge pressure that pushes the
piston up and down; a connecting rod passes
the force to crankshaft, ultimately into rotary
motion. Through the transmission and drive
shaft, power is transferred to the drive
wheels, promoting the car forward.
1.Vehicle’s Power Source
2. Engine’s Power From combustion
The reason why engines can generate power
is actually explosion in cylinder. In sealing the
cylinder combustion chamber, the spark plug
will ignite a certain proportion of the mixed
gas of gasoline and air instantly, generating a
great explosive power.
2. Engine’s Power From combustion
Because the top of the combustion chamber is
fixed, great pressure forces the piston down
by pushing the crank rod. Through a series of
institutions the power is delivered to the
wheels, and ultimately pushes the car.
2. Engine’s Power From combustion
3. Two Types of Engines
V Type
Combine adjacent cylinders at an angle. The
side looks like a V shape.
Advantages: decreased height and length;
lower the hood to meet aerodynamic
requirements; reduce vibration
3. Two Types of Engines
Disadvantages: must use two cylinder heads;
structure is relatively complicated; increased
width
3. Two Types of Engines
W Type
Change the side angle of V type, and here is W
type.
Advantages: shorter crankshaft, lighter weight
Disadvantages: more width, more vibration,
fuller engine compartment, only a little
applications on cars
3. Two Types of Engines
4. The Principle -- Piston Motion
The engine is able to provide a steady stream
of power, thanks to the cylinder intake,
compression, acting methodically, to exhaust
these four stroke cycle operations.
4. The Principle -- Piston Motion
Intake stroke, the piston moves from the top
to the bottom when the intake valve opens,
the exhaust valve is closed, fresh air and fuel
mixture is sucked into the cylinder.
Compression stroke, intake and exhaust valves
closed, the piston moves from the bottom to
the top. Mixed gas is compressed to the
cylinder, in order to raise the temperature, to
prepare for the power stroke.
4. The Principle -- Piston Motion
Power stroke, the spark plug ignites the
compressed gas, a mixed gas generates
"explosion" in the cylinder. The enormous
pressure pushes the piston from the top to the
bottom, the crankshaft is rotated by the push
rod.
4. The Principle -- Piston Motion
Exhaust stroke, the piston moves from the
bottom to the top, at this time the intake
valve is closed, the exhaust valve opens, the
exhaust gas after combustion is discharged
outside the cylinder through the exhaust
manifold.
Conclusion
An engine is the heart of a car. It has been
developed and improved to suit modern
society as the world changed.
References
http://www.pcauto.com.cn/tech/234/2343749_all.html
http://airplanegroundschools.com/Aircraft-Systems/Powerplant/
http://oppositelock.jalopnik.com/w-engine-wednesday-w12-engine-edition-474371162
http://www.4wheelsnews.com/lamborghini-reveals-new-700-hp-v12-engine-and-isr-transmission/
http://www.dieselpowermag.com/tech/1208dp_how_it_works_diesel_engines/photo_01.html