About this previous year paper
The B.Tech Applied Thermodynamics (NME401) question paper from the 2016–17 IV Semester Theory Examination is a comprehensive 100-mark, 3-hour exam designed to assess students’ understanding of steam and gas power cycles, boilers, turbines, nozzles, combustion, jet propulsion systems, and Rankine cycle numericals.
The structure and content of this paper are identical to the thermodynamics papers EME401 and ME403, ensuring uniformity across different branches. The exam is divided into three main sections, each testing different levels of thermodynamic proficiency.
SECTION – A (Short Answer Questions, 20 Marks)
This section consists of 10 questions of 2 marks each, testing fundamental thermodynamic definitions and concepts.
Topics include:
Adiabatic flame temperature Meaning of thrust augmentation in jet engines
Sources of air leakage in condensers
Importance of equivalent evaporation when comparing boilers
Concept of cogeneration (combined heat and power)
How regeneration improves gas turbine thermal efficiency
Classification of condensers (surface, jet, evaporative)
Saturation curve and missing quantity
Types of compounding in turbines (velocity, pressure, pressure-velocity)
What a ramjet engine is
These questions ensure clarity in essential terminology used throughout steam and gas power studies.
SECTION – B (Descriptive & Numerical Questions, Any 5 × 10 = 50 Marks)
This section demands descriptive explanations, cycle sketches, and numerical calculations involving thermodynamic processes.
1. Gas Turbine Cycles with Modifications
Explain gas turbine cycle with:
Intercooling
Reheat + Regeneration
Reheat + Intercooling
2. Choked Flow & Nozzle Friction
Definition of choked flow, sonic velocity conditions, and the effect of friction on nozzle efficiency and mass flow.
3. Steam Engine Indicator Diagrams
(i) Hypothetical vs actual indicator diagrams, diagram shape explanation
(ii) Meaning of diagram factor, plus explanation of saturation curve & missing quantity
4. Rankine Cycle with Reheat – Numerical
Steam entering HP turbine: 20 MPa, 500°C
Exiting LP turbine: 90% dryness
Condenser pressure: 0.005 MPa
Reheated to 500°C
Students determine:
HP turbine exit pressure
Thermal efficiency of the cycle
5. Babcock & Wilcox Boiler
Neat sketch, working, features, water circulation, and advantages.
6. Natural Draught Chimney Numerical
Given:
Height = 60 m Flue gas temp = 300°C
Ambient air = 17°C Air requirement = 19 kg/kg fuel
cp = 1.0032 kJ/kg·K Fuel calorific value = 32604 kJ/kg
Artificial draught exit: 150°C
Calculate:
(i) Draught (mm of water)
(ii) Chimney efficiency
(iii) Heat lost via flue gases per kg fuel
7. Combustion Analysis (C₈H₁₈ + Air)
Determine % CO₂ by volume in dry exhaust gas (CO₂, CO, N₂ considered).
8. Steam Nozzle Expansion
Steam expands: 16 bar → 5 bar, T = 300°C, ṁ = 1 kg/s
Calculate throat & exit areas for:
(i) Frictionless expansion
(ii) 10% friction loss
SECTION – C (Long Analytical Problems, Any 2 × 15 = 30 Marks)
This section includes advanced cycle analysis and turbine velocity diagram calculations.
Q3 – Ideal Rankine Cycle (100 MW Output)
Steam:
Turbine inlet: 8 MPa, saturated vapour Condenser exit: 0.008 MPa, saturated liquid
Students must calculate: Thermal efficiency
Back work ratio Steam mass flow rate (kg/h)
Q4 – Jet Propulsion + Impulse Turbine Numerical
(a) Principles of:
Jet propulsion Turbojet engine
Turboprop engine Rocket propulsion
(b) Turbine data:
Mass flow = 5 kg/s Rotor diameter = 1.2 m
Speed = 3000 rpm Nozzle angle = 18°
Blade speed ratio = 0.4 Velocity coefficient = 0.9
Outlet angle = inlet angle – 3° Students compute:
Blade inlet & outlet angles Power developed
Q5 – Single Stage Impulse Turbine (Velocity Diagram Problem)
Given:
Isentropic enthalpy drop = 200 kJ/kg
Nozzle efficiency = 96%
Nozzle angle = 15°
Blade velocity coefficient = 0.96
Blade speed ratio = 0.5
Steam mass flow = 20 kg/s
Steam inlet velocity = 50 m/s
Determine:
(i) Blade angles (smooth entry & axial exit)
(ii) Blade efficiency
(iii) Power in kW
(iv) Axial thrust