Applied Thermodynamics SPPU Endsem Question Paper May 2023

Questions

1. Q1

   1. a)

      Draw P - θ diagram and explain the different stages of combustion in SI engine.

      Also asked:May 2024

      [8]
   2. b)

      List down the various sensors used in the Electronic Fuel Injection system. Draw and explain D-MPFI system.

      [9]
   OR

2. Q2

   1. a)

      What is knocking in CI Engine? Differentiate knock in SI and CI engines.

      [8]
   2. b)

      What is ignition delay in CI engines? Explain any three factors affecting the ignition delay.

      Also asked:May 2024

      [9]

3. Q3

   1. a)

      What are the different methods used to measure friction power? Explain anyone method with a neat sketch.

      [9]
   2. b)

      In a test of four cylinder, four stroke Petrol engine 75 mm bore and 100 mm stroke, the following results were obtained at full throttle at a particular constant speed and with a fixed setting of fuel supply 6.0 kg/hr. BP with all cylinders = 15.24 kW BP with cylinder no. 1 cut out = 11. kW BP with cylinder no. 2 cut out = 11.03 kW BP with cylinder no. 3 cut out = 10.88 kW BP with cylinder no. 4 cut out = 10.66 kW Calorific value of the fuel = 43600 kJ/kg Clearance volume = 0.0001 m 3 . Calculate : i) Mechanical efficiency ii) Indicated thermal efficiency iii) Air standard efficiency

      [9]
   OR

4. Q4

   1. a)

      Define the following terms with their formula (any four) : i) Indicated power ii) Friction power iii) Mean effective pressure iv) Volumetric efficiency v) Brake specific fuel consumption vi) Brake thermal efficiency

      [9]
   2. b)

      During the trial of a single cylinder, four stroke oil engine, the following results were obtained : Cylinder diameter = 20 cm, Stroke = 40 cm, Mean effective pressure = 6 bar, Torque = 407 Nm, Speed = 250 rpm, Fuel consumption = 4 kg/hr, C.V. of fuel = 43 MJ/kg, Cooling water flow rate = 4.5 kg/min, Air used per kg of fuel = 30 kg of air/kg of fuel, Rise in cooling water temperature = 45 °C, Temperature of exhaust gases = 420 °C, Room temperature = 20 °C, Mean specific heat of exhaust gas = 1 kJ/kg-K, Specific heat of water = 4.18 kJ/kg-K. Calculate : i) Indicated power ii) Brake power iii) Also, thaw a heat balance sheet for the test.

      Also asked:May 2024

      [9]

5. Q5

   1. a)

      Explain with neat sketch pump assisted thermo-syphon water-cooling systems. Differentiate between air-cooling and water-cooling system.

      Also asked:May 2024

      [8]
   2. b)

      Draw neat sketch wet sump lubrication system. Differentiate between wet sump and dry sump lubrication system.

      Also asked:Nov 2025

      [9]
   OR

6. Q6

   1. a)

      Explain magneto ignition system and state its advantages and disadvantages.

      Also asked:May 2024 ·Nov 2023

      [8]
   2. b)

      What is supercharging? Differentiate between supercharging and turbocharging.

      [9]

7. Q7

   1. a)

      Write a short note on capacity control of compressors.

      [9]
   2. b)

      A single acting reciprocating air compressor has cylinder diameter and stroke of 200 mm and 300 mm respectively. The compressor sucks air at 1 bar and 27 °C and delivers at 8 bar while running at 100 rpm. Find : i) Indicated power of the compressor ii) Mass of air delivered by the compressor per minute and iii) Temperature of the delivered by the compressor. The compression follows the law PV 1.25 = C. Take R = 287 J/kg K.

      [9]
   OR

8. Q8

   1. a)

      What is multi-stage compression? Justify it save power required for compression as compared to single stage compression.

      Also asked:May 2024

      [9]
   2. b)

      This part has equations that don’t show as text. Open the PDF to read it.

      [9]