MECH 237 Study Guide - Final Guide: Wet-Bulb Temperature, Liquefaction Of Gases, Humidity
1 May 2017
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Document Summary
The most efficient cycle operating between a heat source at temperature th and a sink at temperature tl is the carnot cycle, and its thermal efficiency is: Th, carnot = 1 : the actual gas cycles are rather complex. The approximations used to simplify the analysis are known as the air-standard assumptions. The air-standard assumptions are called cold- air-standard assumptions if air is also assumed to have constant specific heats at room temperature. In reciprocating engines, the compression ratio r and the mean effective pressure mep are defined as: r = Mep : the otto cycle is the ideal cycle for the spark-ignition reciprocating engines, and it consists of four internally reversible processes: isentropic compression, constant-volume heat addition, isentropic expansion, and constant-volume heat rejection. Under cold-air-standard assumptions, the thermal efficiency of the ideal otto cycle is: Th, otto = 1 : the diesel cycle is the ideal cycle for the compression- ignition reciprocating engines.
