The Evolution Of Jet Engines :: essays research papers

The Evolution of Jet Engines The jet engine is a complex propulsion device which draws in air by means of an intake, compresses it, heats it by means of an internal combustion engine, which when expelled it turns a turbine to produce thrust, resulting in a force sufficient enough to propell the aircraft in the opposite direction (Morgan 67). When the jet engine was thought of back in the 1920's the world never thought it would become a reality, but by 1941 the first successful jet flight was flown in England. Since then the types of engines have changed, but the basic principals have remained the same. In 1921 thoughts of a jet engine were based upon adaptations of piston engines and were usually very heavy and complicated. These thoughts were refined in the 1930's when the turbine engine design lead to the patent of the turbojet engine by Sir Frank Whittle of Great Britian. It was Sir Whittle's design that lead Great Britian into the jet age with the first successful flight. At the same time, the Germans were designing there own jet engine and aircraft which would be one of the factors that kept Germany alive in World War II. With technological advances by the allies a prototype turbojet known as the "Heinkel He 178" came into a few operational squadrons in the German, British, and the American air forces towards the end of World War II. These jets finally helped the allies to win the war against the axis powers(Smith 23-27). A later development in the jet industry was the overcoming of the sound barrier and establishing normal operations up to and beyond twice the speed of sound. Also air force bombers and transports were able to reach and cruise at supersonic speeds(Silverstein 56-70). In the late 1950's civil transcontinental jet services started with the Comet 4 and the Boeing 707. In the mid 1960's all major jet manufacturing companies revised their present engines with new materials such as aircraft aluminium which made them lighter and turbine changes so they could compress the air at a much higher pressure so the engine can produce much more thrust.The first supersonic airliner is the twin turbojet Concorde which flies at over twice the speed of sound which was brought into regular service in 1976(Smith 27-30). The one company that dominates the private jet industry is Bombardier which makes the Learjet turbofans, they have an approximate cruising distance of 1880 nautical miles(Jennings 103). In the future, turbojet engines will continue to further develop due to the technological advances made. As in graphite composite wings, thermoplastic

Environmental Analysis Essay

Introduction This essay will discussed one of the most controversial environmental issue climate change along with some of the facts including how people first discover that climate change does existed; as well as legitimation in climate change globally; public debate; and the way in which government response to this issue. Furthermore this paper will discuss the role of science to identify the existence of climate change. Identification and legitimation of the issue Climate change is one of the biggest environmental challenges that the world encounters. It has obvious impact on our planet causing higher temperature, shifting seasons, sea levels rising. These phenomenon are closely tide up with world’s economic as it affect businesses around the world. The British government report warned if no action is taken to control carbon emissions climate change would cost 5 to 20 percent of the annual global gross domestic product. (Climate change impacts, 2011). The United Nation’s intergovernmental Panel on Climate change published a report in 2007 regarding the discovery of Global Warming since the 20th Century. (IPCC, 2011). The possible reason for this phenomenon may be caused by human activity. The appropriate definition is explained by the IPCC, which states that climate change is â€Å"a change of climate which is attributed directly or indirectly to human activity that alters the composition of the global atmosphere and which is in addition to natural climate variability observed over comparable time periods.† (IPCC, 2012) Many countries have taken the initiative to legislate appropriate regulation regarding climate change. In 2010 a published article noted that â€Å"Qinghai† is one of the first province to establish a regulation that holds local government and state owned enterprises response in coping with climate change (Xinhuanet, 2010). The statistic have shown that â€Å"Qinghai† ‘s temperature in general has been rising by 0.35 centigrade every ten years compare to the world’s average of 0.13 centigrade. (Mu Xuequan, 2010). This regulation will stress the importance and specified the local government’s responsibility on climate change. Public Debate The argument around the topic of climate change is one of the most controversial topic because it involved in whether climate change is man made or its simply nature forces. Some scientist believes that the temperature of earth is actually getting colder not warmer due to the cycle of the sun. This is known as the â€Å"Sunspot cycle†, sun gets a little bit hotter and colder every 11 years and when it gets colder it causes the temperature of earth to get colder too. Other scientist argued that the change of temperature is so small that it can barely be detected. Most scientists agree that an increase in the amount of carbon dioxide in the atmosphere is the main cause of global warming. They argued about the details of the effects of global warming on the earth. However it is generally agreed that it will lead to worldwide changes in weather patterns, gradual melting of the ice caps and rising sea levels. These changes will impact on your lifestyle, agriculture and the survival of other organism. (Haire, M et al, 2000). Energy savings, emissions reductions and water resource conservation and many other works related to climate change need to be considered Government policy response Recent years many countries have impose law relevant to combat climate change. Energy savings, emissions reductions and water resource conservation and marketing â€Å"green† have been the primary goal amongst most organization. Country like Australia is promoting energy efficiency measures through a wide range of programs and rebates. The election of Kevin Rudd in 2007 especially shows a major change of the Australian government policy through Australia’s ratification of the Kyoto Protocol. In terms of some specific initiatives the Australian government also continue the measure of mandatory renewable energy target scheme. And since 2010 the Government also established a climate change committee with the main purpose of investigate â€Å"options for implementing a carbon price and help build consensus on how Australia will tackle climate change† (Parliament of Australia, 2012) Role of science Science has played an important part in proving the existence of climate change by observation and experiment. This graph above depicts the global change in sea level since the end of the last ice age. During this 15,000 year period sea level has increased approximately 125 meters. Conclusion By evaluating the historical development of climate change we can conclude that climate change is the most important and challenging environmental issue. Regardless of the disagreements, climate change has been proven exist by scientific research. It has drawn the public attention and requires international cooperation among different governments. Reference Haire, M et al (2000). Core Science3. Singapore: Kyodo. P110-111. IPCC (2011) Intergovernmental Panel on Climate Change. [online] Available at; http://www.ipcc.ch/pdf/assessment-report/ar4/syr/ar4_syr_cn.pdf [Accessed: 27 Jul 2012]. Parliament of Australia (2012) Australian government response to climate change. [online] Available at: http://www.aph.gov.au/About_Parliament/Parliamentary_Departments/Parliamentary_Library/Browse_by_Topic/ClimateChange/Governance/Domestic/national [Accessed: 27 Jul 2012]. Sunspots and climate (2000) Sunspots and climate. [online] Available at: http://www-das.uwyo.edu/~geerts/cwx/notes/chap02/sunspots.html [Accessed: 27 Jul 2012]. The Nature Conservancy (2012) Climate Change Impacts. [online] Available at;

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