Spark Ignition (Gasoline) Engines
From Thermal-FluidsPedia
Most passenger cars operating today are spark ignition; their engines work by allowing a mixture of fuel and air prepared in a carburetor to burn and expand inside the cylinders. The downward motion of a piston is converted to rotational motion of the crankshaft by means of connecting rods and eventually, by way of a transmission, to the wheels.
The rotary (Wankel) engine is a special type of spark ignition engine in which the piston-cylinder assembly is substituted by a three-edged rotor mounted off-center of a specially designed housing. Unlike conventional engines where the four strokes are accomplished by linear up and down motions of the pistons, rotary engines work by varying the volume as the rotor rotates in the housing. The main advantages of rotary engines are their lower mass and volume as compared to reciprocating engines of comparable power rating and their simpler construction. Furthermore, because rotary engines deliver power directly in rotational form, their overall efficiency is higher. The main disadvantage is that rotors are more difficult to seal, which makes hydrocarbon emission higher. Basic operation of reciprocating and rotary engines is described in Figure 1.
Table 1. US Passenger Travel and Energy Use, 2004 Mode Number of Vehicles Passenger-miles (billions) % of total travel Load Factor
(persons/vehicles)BTU/passenger-miles Automobiles
Light trucks
Motorcycles
Busesa Planesb
Rails136 million
81 million
5.4 million
695,000
219,000
18,6002,669
1,479
11
21
549
3156
31
0.2
0.3
12
0.61.6
1.7
1.1
8.7c
90
243,496
4,329
2,272
4,318c
3,959
2,978a Includes transit, intercity, and school; b General aviation; c Data available for transit buses only
Ref: Davis, S. C., Diegel, S. W., Table 2.12. “Transportation Energy Data Book,” ORNL-6978, Edition 26, 2006.
References
(1) Toossi Reza, "Energy and the Environment:Sources, technologies, and impacts", Verve Publishers, 2005
Further Reading
Tillman, D., Fuels of Opportunity: Characteristics and Uses In Combustion Systems, Academic Press, 2004.
Sorensen, K., Hydrogen and Fuel Cells: Emerging Technologies and Applications, Academic Press, 2005.
Dhameia, S., Electric Vehicle Battery Systems, Academic Press, 2001.
Hussain, I., Electric and Hybrid Vehicles: Design Fundamentals, CRC Press, LLC. 2003.
Jefferson, C.M., and Barnard, R. H., Hybrid Vehicle Propulsion, WIT Press, 2002.
Spelberg, D. The Hydrogen Energy Transition: Moving Toward the Post Petroleum Age in Transportation, Academic Press, 2004.
Fuel, Direct Science Elsevier Publishing Company, Fuel focuses on primary research work in the science and technology of fuel and energy fuel science.
Transportation Research Part C: Emerging Technologies, Direct Science Elsevier Publishing Company; this journal focuses on scholarly research on development, application, and implications in the fields of transportation, control systems, and telecommunications, among others.
Fuel Cells Bulletin, Direct Science Elsevier Publishing Company, Fuel Cells Bulletin is the leading source of technical and business news for the fuel cells sector.
International Journal of Hydrogen Energy, Direct Science Elsevier Publishing Company, Quarterly journal covering various aspects of hydrogen energy, including production, storage, transmission, and utilization, as well as economical and environmental aspects.
External Links
US Department of Transportation (http://www.dot.gov).
US Department of Energy (http://www.doe.gov).
US Environmental Protection Agency (http://www.epa.gov).
National Energy Renewable Laboratory Hybrid Electric &Fuel Cell Vehicles (http://www.nrel.gov/vehiclesandfuels/hev).
FreedomCar (http://www.eere.energy.gov/vehiclesandfuels).