MECHENG 235 Lecture Notes - Lecture 5: Polytropic Process, Thermodynamics
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Me 235 thermodynamics i / winter 2014 / section 002. 3. 124 a piston cylinder (0. 5 kg steel altogether) maintaining a constant pressure has 0. 2 kg r-134a as saturated vapor at 150 kpa. It is heated to 40 c and the steel is at the same temperature as the r-134a at any time. Find the work and heat transfer for the process. 3. 160 a piston/cylinder arrangement of initial volume 0. 025 m3 contains saturated water vapor at 180 c. The steam now expands in a polytropic process with exponent n = 1 to a final pressure of 200 kpa, while it does work against the piston. 3. 184 air in a rigid tank is at 100 kpa, 300 k with a volume of 0. 75 m3. The tank is heated to 400 k, state: now one side of the tank acts as a piston letting the air expand slowly at constant temperature to state 3 with a volume of 1. 5 m3.