About this previous year paper
The B.Tech Applied Thermodynamics (EME401) question paper from the 2016–17 IV Semester Theory Examination is a 100-mark, 3-hour comprehensive assessment covering gas turbines, steam boilers, Rankine cycle, jet propulsion, combustion, condensers, turbines, nozzles, chimneys, and thermodynamic performance calculations. The paper is divided into three extensive sections testing conceptual clarity, cycle analysis, numerical proficiency, and engineering application skills.
SECTION – A (Short Answer Questions, 20 Marks)
This section consists of 10 questions of 2 marks each, covering fundamental thermodynamic concepts and components used in power generation and propulsion.
The topics include:
Adiabatic flame temperature definition
Meaning of thrust augmentation in jet engines
Sources of air leakage in condensers
Use of equivalent evaporation for boiler comparison
Concept of cogeneration for combined heat & power
Effect of regeneration in gas turbines on thermal efficiency
Classification of condensers (jet, surface, evaporative, etc.)
Saturation curve and missing quantity in boilers/steam tables
Compounding in turbines (pressure, velocity, pressure-velocity compounding)
Definition of Ramjet propulsion
These basic questions ensure understanding of key terminologies and principles.
SECTION – B (Descriptive & Numerical Questions, Any 5 × 10 = 50 Marks)
This section includes medium-length problems requiring detailed explanation, thermodynamic analysis, diagrams, and numerical calculations.
1. Gas Turbine Cycles
Explaining gas turbine cycle modifications:
With intercooling
With reheat & regeneration
With reheat & intercooling
2. Choked Flow & Nozzle Friction
Definition of choked flow, its thermodynamic significance, and friction effects in nozzles.
3. Steam Engine Indicator Diagram
(i) Hypothetical vs actual indicator diagram
(ii) Diagram factor explanation
plus explanation of saturation curve & missing quantity.
4. Rankine Cycle Problem with Reheat
Steam enters HP turbine at 20 MPa, 500°C, leaves LP turbine at 90% dryness, condenser pressure 0.005 MPa, reheated to 500°C.
Students must determine:
Pressure at exit of HP turbine
Thermal efficiency
5. Babcock & Wilcox Boiler
Construction, working, features, and water circulation explained with a neat sketch.
6. Natural Draught Chimney Problem
Given: 60 m high chimney, flue gas temperature 300°C, atmospheric 17°C
Students calculate:
(i) Draught in mm of water
(ii) Chimney efficiency
(iii) Heat carried away by flue gases per kg of fuel
7. Combustion Problem (C₈H₁₈ with Air)
Calculate percentage by volume of CO₂ in dry exhaust gas using fuel–air ratio and combustion products.
8. Steam Nozzle Flow
Steam expansion from 16 bar → 5 bar, initial T = 300°C, mass flow 1 kg/s
Calculate throat & exit areas for:
(i) Frictionless flow
(ii) 10% friction loss
SECTION – C (Long Analytical Questions, Any 2 × 15 = 30 Marks)
These questions require deep thermodynamic reasoning, cycle evaluation, and turbine/jet propulsion engineering.
Q3 – Ideal Rankine Cycle Analysis (100 MW plant)
Steam:
Saturated vapour at 8 MPa enters turbine Saturated liquid at 0.008 MPa exits condenser
Students must determine: Thermal efficiency
Back work ratio Mass flow rate (kg/h) of steam
Q4 – Jet Propulsion + Impulse Turbine Problem
(a) Principles of:
Jet propulsion Turbojet engine
Turboprop engine Rocket propulsion
(b) Impulse turbine problem:
Given:
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 blade angle = 3° less than inlet Students determine:
Blade angles Power developed
Q5 – Single Stage Impulse Turbine with Given Parameters
Given:
Isentropic enthalpy drop = 200 kJ/kg Nozzle efficiency = 96%
Nozzle angle = 15° Blade velocity coefficient = 0.96
Blade speed ratio = 0.5 Mass flow = 20 kg/s
Steam inlet velocity = 50 m/s
Find:
(i) Blade inlet & outlet angles
(ii) Blade efficiency
(iii) Power developed (kW)
(iv) Axial thrust
This requires a detailed velocity diagram solution.