MAE 204 Lecture Notes - Lecture 17: Irreversible Process, The 2Nd Law

• School: University at Buffalo
• Department: Mechanical & Aerospace Engr
• Course: MAE 204
• Professor: Salac David

Document Summary

Any property integrated around a cloed cycle, is zero. since q/tfor an internaly rev. system. Even though entropy was defined using an internally reversible system, entropy is a proerty for all system. T-s plot it looks similar from before p-v diagram: h-s plot (mollian diagram. Look at a 2 processs cycle. prcoes 1 to 2 any process process 2 to 1 int. reversible. Q/t = integral 1 to 2 q/t + integral 2 to 1 q/t int rev <=0. The energychange of the system equals the net energy into the system, Look at entropy s2-s1 >= integral from 1 to 2 q/t. The entropy change of the system might be bigger than the amount added( assume. It is impossible for any system to operate in a way that entropy is destrayed. - s gen >= 0 s2 -s1 = integral from 1 to 2 q/t +sgen w/ sgen>0.