Question

A Piston-cylinder heat engine containing a monatomic ideal gas undergoes the three processes drawn on the p-V diagram below. The gas is initially at room temperature (300 K). Determine the total work done by the gas, and the total heat flow into the gas after completing one cycle. What is the thermal efficiency of this engine?

Problem Statement A piston-cylinder heat engine containing a monatomic ideal gas undergoes the three processes drawn on the p-V diagram below. The gas is initially at room temperature (300 K). Determine the total work done by the gas, and the total heat flow into the gas after completing one cycle. What is the thermal efficiency of this engine? Visual Representation • Draw the pV diagram of the cycle (if not already given). • Identify the type of each process. p (kPa) 400 200 V(cm) 100 200 Mathematical Representation • Determine p. V and T at the beginning and end of each process • Calculate Q. Wy, and AE for each process • Verify that (AE O . • Calculate desired quantities,

Answer 1

7 P (pressure). [kPa] ko It a >.(volume) TUO 200 [cm3 Determine the total Work done by the gles, and total heat flow in to the gas after completing one cycle. The work done by the gees is total area enclosed by triangle. work done = £ (base) (height) = = [2 00 -100] [400-300] 2' [100] [200] - 109 cm3. (K.pa) = 106. [16-?) [103 x IN Answord = 1 Nom n2 Inork done = I Jouler

For total a one change complet in i cycle change in iternal energy is ere. Louzo By using low of thermodynamics. Du = sce-ow DQ = I Joule Ansog. The tured heat flow is I Joule. hermal efficiency = n ermal efficiency Dw AWI 1 thermal efficieny of heat Answerin engine The I. is