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11/19/2012PHY 113 A Fall 2012 -- Lecture 321 PHY 113 A General Physics I 9-9:50 AM MWF Olin 101 Plan for Lecture 32: Chapter 22: Heat engines 1.Thermodynamic cycles; work and heat efficiency 2.Carnot cycle 3.Otto cycle; diesel cycle 4.Note – in this class, we will not focus on entropy and the second law of thermodynamics
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11/19/2012 PHY 113 A Fall 2012 -- Lecture 322
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11/19/2012PHY 113 A Fall 2012 -- Lecture 323 Thermodynamic cycles for designing ideal engines and heat pumps P (1.013 x 10 5 ) Pa ViVi VfVf PiPi PfPf A BC D Engine process: http://auto.howstuffworks.com/engine1.htm
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11/19/2012PHY 113 A Fall 2012 -- Lecture 324 P (1.013 x 10 5 ) Pa ViVi VfVf PiPi PfPf A BC D Examples process by an ideal gas: ABABBCBCCDCDDADA Q W0-P f (V f -V i )0P i (V f -V i ) E int
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11/19/2012PHY 113 A Fall 2012 -- Lecture 325 Example from homework
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11/19/2012PHY 113 A Fall 2012 -- Lecture 326 Most efficient thermodynamic cycle -- Carnot Sadi Carnot 1796-1832
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11/19/2012PHY 113 A Fall 2012 -- Lecture 327 Carnot cycle: A B Isothermal at T h B C Adiabatic C D Isothermal at T c D A Adiabatic
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11/19/2012PHY 113 A Fall 2012 -- Lecture 328 iclicker exercise: We discussed the efficiency of an engine as Is this result A.Special to the Carnot cycle B.General to all ideal thermodynamic cycles iclicker exercise: We discussed the efficiency of an engine running with hot and cold reservoirs as Is this result A.Special to the Carnot cycle B.General to all ideal thermodynamic cycles
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11/19/2012PHY 113 A Fall 2012 -- Lecture 329
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11/19/2012PHY 113 A Fall 2012 -- Lecture 3210 iclicker exercise: Why should we care about the Carnot cycle? A.We shouldn’t B.It approximately models some heating and cooling technologies C.It provides insight into another thermodynamic variable -- entropy
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11/19/2012PHY 113 A Fall 2012 -- Lecture 3211 The Otto cycle
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11/19/2012PHY 113 A Fall 2012 -- Lecture 3212 The Diesel cycle
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11/19/2012PHY 113 A Fall 2012 -- Lecture 3213
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11/19/2012PHY 113 A Fall 2012 -- Lecture 3214 Engine vs heating/cooling designs
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