Open Worksheet 4 Transportation Engines Power Point 4

Propulsion Gasoline Piston Engine – An engine found in automobiles, motorcycles, lawn mowers, and snowmobiles. These engines have 5 main components: A cylinder, piston, spark plug, crankshaft and fuel.

Cylinder - An enclosed chamber with two ports, One allows fuel and air in, the other allows exhaust to escape. Piston - The main moving part, compresses the air and fuel mixture.

Spark Plug - Ignites the compressed fuel Crankshaft - Device that transmits power of the engine to the transmission.

Parts: C: Crankshaft E: Exhaust valve camshaft I: Inlet valve P: Piston R: Connecting rod S: Spark plug V: Valves. W: Cooling water ducts

Engine Types Gasoline Piston Engines are classified by the quantity and alignment of cylinders. 3 Main Configurations Inline Flat / Opposed V Engine

Inline

Flat / Opposed

V-engine

Rotary Engine Uses rotors instead of pistons. Engine is small, powerful and smooth running Housing has special shape called and epitrochoidal curve, like a large figure 8. It allows the tips of the rotor to ride against the housing.

Rotary Engine Use more fuel than conventional engines and are greater pollutants.

Diesel Engines Invented by Rudolf Diesel, Patented July 16, 1895. An internal combustion engine that uses heat and pressure to ignite its fuel. Can also be called a compression-ignition engine.

Diesel Engines The diesel internal combustion engine differs from the gasoline engine by using highly compressed hot air to ignite the fuel rather than using a spark plug In the true diesel engine, only air is initially introduced into the combustion chamber. The air is then compressed with a compression ratio typically between 15:1 and 22:1

Diesel Engines The heat of the compressed air then ignites the injected fuel. Diesel engines have a high compression ratio compared to gasoline engines and are built much stronger to support the stress of the high compression

Electrical Propulsion Two Types Direct electric vehicles Requires a connection to electricity Bumper cars connect to electric grid on the ceiling Subway trains use a third rail to provide power.

Indirect Electric Vehicles Can be powered by batteries Batteries charged either by plugging in vehicle or using electricity generating devices. Solar Panels or Photovoltaic Cells can be used to charge batteries but are not efficient Fuel Cells are a new technology that is being designed for automobiles. It is a device that utilizes a chemical reaction between hydrogen and oxygen to produce electricity. Byproducts of a fuel cell are only heat and water.

Electromagnetic Propulsion Generally called magnetic levitation or maglev. Propelled by the magnetic field generated by the electromagnets. The guideways are lined with electromagnets which repel the train making it float. These frictionless trains can reach speeds of 300MPH+

Hybrid Vehicles Use both internal combustion engine and electric motor. Two types Series hybrid – Gasoline motor powers a generator which charges the batteries, the electric motor then uses the batteries to supply power to the wheels

Hybrid Vehicles Parallel hybrids – Uses both the gasoline and electric engine to power the wheels. Electric motor is used at low speeds, less than 25mph, gasoline engine used at greater speeds 25mph+. Sometimes both are used if extra power is needed, such as passing cars on the highway. Regenerative Braking – process that transforms a car’s kinetic energy into electrical energy by using the electric motor as a generator during braking.