JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD
JAWAHARLAL NEHRU TECHNOLOGICAL UNIVERSITY HYDERABAD B. Tech II THERMAL SCIENCE Previous Question Paper (April/May - 2023 - R18)
Note: i) Question paper consists of Part A, Part B. ii) Part A is compulsory, which carries 25 marks. In Part A, Answer all questions. iii) In Part B, Answer any one question from each unit. Each question carries 10 marks and may have a, b as sub questions.
Part A
Define the universe.
Answer
In thermodynamics, the universe is defined as the combination of the system and its surroundings. It represents the total region of space and matter involved in a thermodynamic process, encompassing everything that can interact with or be affected by the system under study.
Recall the control volume with some examples.
Answer
A control volume is a fixed region in space chosen for thermodynamic analysis, through which mass and energy can flow. Unlike a system of fixed identity, the control volume focuses on a specific volume of space, allowing for the study of open systems where matter crosses the boundary.
Examples include:
- Nozzles and Diffusers: Where fluid enters and leaves a defined geometry to change velocity and pressure.
- Turbines and Compressors: Devices where work is transferred to or from a flowing fluid stream.
- Heat Exchangers: Where energy is transferred between two fluid streams separated by a solid boundary within the control volume.
State the first law of thermodynamics.
Answer
Sign in to view the complete answer paper.
Recall the importance of ideal gas temperature scale.
Answer
Sign in to view the complete answer paper.
Define entropy.
Answer
Sign in to view the complete answer paper.
What is a heat pump? Define COP of heat pump.
Answer
Sign in to view the complete answer paper.
State the processes involved in Otto cycle.
Answer
Sign in to view the complete answer paper.
Summarize the importance of volumetric efficiency.
Answer
Sign in to view the complete answer paper.
Recall the functions of connecting rod.
Answer
Sign in to view the complete answer paper.
List the advantages of water tube boilers.
Answer
Sign in to view the complete answer paper.
Part B
State the differences between the work transfer and heat transfer.
Answer
Sign in to view the complete answer paper.
Explain the thermodynamic equilibrium in detail.
Answer
Sign in to view the complete answer paper.
Why all the actual process are irreversible. Justify the statement with real examples.
Answer
Sign in to view the complete answer paper.
Interpret the concepts of state property, process and cycle with well-known examples.
Answer
Sign in to view the complete answer paper.
Steam is supplied to a fully loaded 1100 kW turbine at 15 bar with an internal energy of 2935 kJ/kg, specific volume of 0.16 m3/kg and velocity of 110 m/s. Exhaust takes place at 0.05 bar with an internal energy of 1885 kJ/kg, specific volume equal to 26 m3/kg and velocity of 300 m/s. Heat loss from the steam in the turbine is 21 kJ/kg. Determine: a) Shaft work output per kg. b) Steam flow rate in kg/h.
Answer
Sign in to view the complete answer paper.
A mass of gas at an initial pressure of 28 bar and with an internal energy of 1500 kJ, is contained in a well-insulated cylinder of volume 0.06 m3. The gas is allowed to expand behind a piston until its internal energy is 1400 kJ, the law of expansion is pv2 = C. Calculate: a) The work done. b) The final volume. c) The final pressure.
Answer
Sign in to view the complete answer paper.
Derive the thermal efficiency of Carnot cycle by showing the processes on p-v and T-s Diagrams.
Answer
Sign in to view the complete answer paper.
Derive Clausius inequality and explain its significance.
Answer
Sign in to view the complete answer paper.
An ideal Otto cycle with air at 1 bar and 23°C as the working fluid has a compression ratio of 8. Determine the pressure and temperature at the end of the heat addition process, the network output, the thermal efficiency, and the mean effective pressure for the cycle. Assume air is an ideal gas with constant specific heats.
Answer
Sign in to view the complete answer paper.
An air standard dual cycle has a compression ratio of 16 and compression begins at 1 bar and 50°C. The maximum pressure is 70 bar. The heat transformed to air at constant pressure is equal to heat transferred at constant volume. Find the temperature at all cardial points, cycle efficiency and mean effective pressure take cp = 1.005 kJ/kgK, cv = 0.718 kJ/kgK.
Answer
Sign in to view the complete answer paper.
Classify the IC engines in detailed and list out the applications of IC engines.
Answer
Sign in to view the complete answer paper.
Describe the working of fuel injector with neat sketch.
Answer
Sign in to view the complete answer paper.
Explain the working of splash lubrication system with neat sketch.
Answer
Sign in to view the complete answer paper.
Discuss the working of battery ignition system with neat sketch.
Answer
Sign in to view the complete answer paper.