Transcript Class_3_-_Subarea_VI

Transportation Technology
MTEL Technology/Engineering
Subarea VI
Types of Transportation
• Rail – Usually a set of two parallel steel rails on
which a train rides. Other methods include
monorail and magnetic levitation
• Air – The use of aircraft propelled by proper air
flow over an airfoil, usually generated with the
use of high speed propellers and or jet engine
technologies
• Road – Using a prepared pathway to travel with
wheels between two points.
• Marine – The use of boats to utilize waterways as
a means of transportation
• Intermodal – The use of multiple transportation
methods to reach a final destination
Internal vs External Combustion
• Internal combustion engine or ICE generates
propulsive force through the combustion of a fuel
within a sealed chamber. This explosive action
causes high pressure gas to give movement to the
piston/turbine/nozzle.
• An External combustion engine or ECE generates
force by using an external fuel source to heat and
cause the expansion of a fluid inside a chamber
to create high pressure gas (steam engine)
ICE vs ECE
Four Stroke Engine Diagram
Two Stroke Engine Diagram
Fossil Fuels
• Created from the decomposition of dead organic
material under great atmospheric pressure over
long periods of time
• Incredibly important to modern transportation as
it is the main source of fuel for nearly every
combustion engine
• Currently not considered a sustainable resource
because demand outstrips the rate or renewal
• The burning of fossil fuels adds to
anthropomorphic climate change
Steam Engine
• Created by boiling water
and then harnessed to
power steam turbines
• Used extensively before
the invention of the ICE
• Currently used more in
energy production then
transportation
• Must use a fuel source,
most often some sort of
fossil fuel
Buoyancy
• The force that
causes object to
float in a fluid
• Generated
because of the
pressure
difference
between the
object and the
fluid it resides in
Momentum
• An objects mass multiplied by it current
velocity
• Indicated both direction and magnitude of the
object
Inertia
• An object innate resistance to changing its
state of motion.
• More massive objects possess more inertia
then less massive ones
Weight
• The force of gravity applied to any object
• Here on earth the gravity we feel is the
gravitational force generated between the
huge mass of the earth when compared with
any other object on the surface of the earth.
• An objects weight will vary according to the
strength of the gravitational field in which it is
situated (on another planet)
Thrust
• A reaction force developed when mass is
expelled or accelerated in one direction,
causing a proportional force in the opposite
direction
• In air transportation it occurs by pushing
airflow over a wing, usually by spinning a
propeller or a fan pulling air through a jet
engine
Four forces of flight
Pneumatics
• Pneumatics is a section of technology that deals with
the study and application of pressurized gas to produce
mechanical motion. Pneumatic systems used extensively
in industry are commonly powered by compressed air or
compressed inert gases
Hydraulics
• The basic idea behind any hydraulic system is very simple: Force
that is applied at one point is transmitted to another point using
an incompressible fluid. The fluid is almost always an oil of some
sort. The force is almost always multiplied in the process. The
picture below shows the simplest possible hydraulic system
• The neat thing about hydraulic systems is that it is very easy to add
force multiplication (or division) to the system.
• In a hydraulic system, all you do is change the size of one piston and
cylinder relative to the other.
In this case applying a
100lb force for
9inches will induce a
900lb force on the
right but for only 1
inch