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QUESTION 1 (15 marks) Part A V. VE The Diesel cycle consists of: A™B-an adiabatic compression BẠC - an isobaric expansion CD-an adiabatic expansion DA-an isochoric depressurisation Assume that the working fluid for this Diesel engine is an ideal gas. (1) Sketch the Diesel cycle on a P-V diagram. On your diagram, mark processes where heat enters and leaves the cycle (Qin and Qout). (1 mark) (ii) Using the first law of thermodynamics, derive expressions for the entropy change in each leg of the Diesel cycle in terms of VA, VB, VC, PA, PB, Pp and the adiabatic exponent, y, i.e. derive expressions for the entropy changes: ASA,B, ASB,C, ASC,D and ASO,4. Eliminate all heat capacities from your answers, expressing them in terms of the requested parameters (Note: you may not need all of these parameters for each expression). (4 marks) (I) Prove that the net entropy change of the gas for one cycle is zero. (2 marks) (iv) Plot the Diesel cycle on a T-S diagram, marking states A, B, C and D while paying careful attention to the temperature and entropy of each state. (1 mark)