Total No. of Questions : 8] SEAT No.
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PB-3711 [Total No. of Pages : 3
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S.E. (Mechanical & Automobile Engineering)
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APPLIED THERMODYNAMICS
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(2019 Pattern) (Semester - IV) (202048)
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Time : 2½ Hours] [Max. Marks : 70
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Instructions to the candidates:
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1) Answer Q1 or Q2, Q3 or Q4, Q5 or Q6, Q7 or Q8.
2) Figures to the right indicate full marks.
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3) Neat diagrams must be drawn whenever necessary.
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4) Make suitable assumption whenever necessary.
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5) Scientific calculator is allowed.
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Q1) a) Explain the various engine variables influences abnormal combustion in
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SI engines. [8]
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b) Classify fuel injection system used in CI Engines and explain working of
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Bosch fuel pump with neat sketch. [9]
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Q2) a) Draw p- diagram and explain the different stages of combustion in SI
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engine. [8]
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b) What is ignition delay in CI engines? Explain any three factors affecting
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the ignition delay. [9]
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Q3) a) During the trial of a single cylinder, four stroke oil engine, the following
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results were obtained: Cylinder diameter = 20cm, stroke = 40cm, mean
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effective pressure = 6bar,Torque = 407 Nm, Speed = 250 rpm, Fuel
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consumption = 4 kg/hr., C.V. of fuel = 43 MJ/kg, Cooling water flow
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rate = 4.5 kg/min, Air used per kg of fuel =30 kg of air / kg of fuel, rise in
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cooling water temperature = 45 °C, Temperature of exhaust gases = 420
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°C, Room temperature = 20 °C, Mean specific heat of exhaustgas = 1
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kJ/kg-K, Specific heat of water = 4.18 kJ/kg-K.Calculate, IP, BP and
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draw heat balance sheet for the test. [10]
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b) Write short note on Indian Driving Cycle and European Driving Cycle.[8]
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OR
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P.T.O.
Q4) a) In a test of a four-cylinder petrol engine of 75mm bore and 100mm
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stroke, the following results were obtained at full throttle at a constant
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speed and with a fixedsetting of the fuel supply of 0.082 Kg/min. [10]
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BP with all cylinder working = 15.24 kW,
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BP with cylinder I is cut-off = 10.45 kW,
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BP with cylinder 2 is cut-off = 10.38 kW,
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BP with cylinder 3 is cut-off = 10.23 kW,
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BP with cylinder 4 is cut-off = 10.35 kW,
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Find,
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i) Total indicated power of the engine,
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ii) Total friction power and
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iii) Indicated thermal efficiency of the engine if the CV of the fliel is
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44MJ/Kg.
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b) Define IP, BP and FP. Explain Willan’s Line Method to find Friction
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Power. [8]
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Q5) a) Explain with neat sketch pump assisted thermo-syphon water-cooling
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systems. Differentiate between air-cooling and water-cooling system.[9]
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b) Explain with neat sketch wet sump lubrication system. Enlist the required
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property of a good lubricant. [8]
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Q6) a) Explain battery ignition system and state its advantages and disadvantages.
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[9]
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b) What is turbocharging? Explain with neat sketch any one turbocharger.
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[8]
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Q7) a) A single stage, single cylinder reciprocating air compressor delivers air
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at 6 bars. The rate of air taken in during suction is 12 kg/min. at 1.013 bar
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and 27°C. the compression take place with the index of 1.25. [9]
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Calculate,
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i) Work required for delivering 1 kg of air.
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ii) Actual power required to run the compressor if mech = 80%.
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b) What is multi-stage compression? Justify it save power required for
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compression as compared to single stage compression. [9]
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Q8) a) A single acting single cylinder reciprocating air compressor has stroke
volume 0.012 m3 at 111rpm. The suction pressure and temperature are
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1.013 bar and 27 °C respectively. The delivery pressure is 8 bar. [9]
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Calculate,
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i) Temperature after compression
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ii) Compression work done required if compression is with index 1.4.
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iii) Isothermal efficiency.
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b) Give the classification of compressor? Differentiate between reciprocating
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and rotary compressor. [9]
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