[熱能]熱力學otto cycle 問題
這題想很久想不出來 Otto cycle:
題目:The compression ration an Otto cycle is Va/Vb = 8.00.At the beginning of
the compression process ,500 cm*3 of gas is at 100kPa and 20度(攝氏).At the
beginning of the adiabatic expansion ,the temperature is 750度(攝氏).Model the
ideal gas with E(int){int是下標}=nCvT=2.5nRT and γ=1.4
Find the number of crankshaft revolution per minute require for a one-cylinder
engine to have an output power of 1000w=1.34hp .
NOTE:The thermodynamic cycle involves four piston strokes.
我看解答是降寫的Let f represent the angular speed of the crankshaft. Then
f/2is the frequency at which we obtain work in the amount of 84.3 J
1000=(f/2) x 84.3
-->f=1.42 x 10*3 rev/min
我不懂的地方是,為什麼要除以二?有人可以告訴我嗎?感激不盡喔!!
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※ 編輯: coffee1205 來自: 123.204.210.150 (03/20 21:56)