Applied Thermodynamics SPPU Endsem Question Paper Nov 2023

Questions

1. Q1

   1. a)

      Outline the various phases involved in combustion in a compression- ignition engine.

      [9]
   2. b)

      Illustrate and provide a concise explanation of the diverse types of combustion chambers in spark-ignition engines.

      [8]
   OR

2. Q2

   1. a)

      Define detonation in a spark-ignition engine and describe the different factors that influence detonation in such engines?

      [8]
   2. b)

      Categorize the fuel injection systems employed in compression-ignition engines, and elucidate the operational mechanics of the Common Rail Diesel Injection system, accompanied by a clear diagram.

      [9]

3. Q3

   1. a)

      The following data were recorded in a test of one-hour duration on a single cylinder oil engine working on four stroke cycle. Bore = 300 mm, stroke = 450 mm, mean effective pressure = 5.8 bar, Brake friction load = 1860 N, Diameter of brake wheel = 1.22m, Fuel used = 8.8 Kg, CV. of fuel = 41800KJ/kg, Average speed = 200 RPM. Calculate i) Mechanical efficiency ii) Brake thermal efficiency

      [10]
   2. b)

      Detail the operational process of the Non-Dispersive Infrared (NDIR) method for measuring emissions? 2

      [8]
   OR

4. Q4

   1. a)

      In a test of a four-cylinder four stroke petrol engine of 75mm bore and 100mm stroke, the following results were obtained at full throttle at a constant speed and with a fixed setting of the fuel supply of 0.082 Kg/min. BP with all cylinder working = 15.24 kW, BP with cylinder 1 is cut-off = 10.45 kW, BP with cylinder 2 is cut-off = 10.38 kW, BP with cylinder 3 is cut-off = 10.23 kW, BP with cylinder 4 is cut-off = 10,45 kW, Find, i) Total indicated power of the engine, ii) Total friction power and iii) Indicated thermal efficiency of the engine if the CV of the fuel is 44MJ/Kg.

      Also asked:May 2024

      [9]
   2. b)

      Explain the following : i) Mean effective pressure ii) Air fuel ratio iii) Heat balance sheet.

      [9]

5. Q5

   1. a)

      What is the magneto ignition system and what are its advantages and disadvantages?

      Also asked:May 2024 ·May 2023

      [9]
   2. b)

      Illustrate a well-labeled diagram of a wet sump lubrication system and provide a comparative analysis distinguishing the features of wet sump and dry sump lubrication systems.

      [8]
   OR

6. Q6

   1. a)

      Elaborate on thermostatic water-cooling systems, providing a detailed illustration. Additionally, distinguish the characteristics of air-cooling and water-cooling systems.

      [9]
   2. b)

      Define supercharging and outline the distinctions between supercharging and turbocharging? 3

      [8]

7. Q7

   1. a)

      A single stage, single acting reciprocating air compressor delivers air 0.7 kg of air per minute at 6 bar. The suction temperature and pressure are 25 °C and 1 bar. The bore and stroke of the compressor are 100 mm and 150 mm respectively. The clearance is 3 % of swept volume. Assuming index of compression and expansion to be 1.3. Calculate, i) Volumetric efficiency of compressor. ii) Actual power required to run the compressor if  mech = 85%.

      Also asked:Nov 2025

      [9]
   2. b)

      Categorize various types of air compressors and provide a list of applications where air compressors are commonly utilized.

      [9]
   OR

8. Q8

   1. a)

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

      [9]
   2. b)

      Define the isothermal efficiency of compressors and elucidate the diverse methods and strategies employed to enhance compressor efficiency. 

      [9]