THEORY EXAMINATION (SEM–IV) 2016-17 APPLIED THERMODYNAMICS

The B.Tech Applied Thermodynamics (ME403) question paper from the 2016–17 IV Semester Theory Examination is a comprehensive 100-mark, 3-hour assessment that evaluates a student's understanding of steam power plants, Rankine cycle analysis, gas turbine systems, boilers, condensers, combustion, jet propulsion, steam nozzles, and turbine velocity diagram calculations.

The paper is divided into three structured sections (A, B, C) to test conceptual knowledge, descriptive understanding, and numerical problem-solving ability.

SECTION – A (Short Answer Fundamentals, 20 Marks)

This section contains 10 questions of 2 marks each, covering the essential elements of applied thermodynamics. Students must define or explain:

Adiabatic flame temperature

Thrust augmentation in jet engines

Sources of air leakage in condensers

Use of equivalent evaporation for boiler performance comparison

Concept of cogeneration

How regeneration improves gas turbine thermal efficiency

Classification of condensers

Definition of saturation curve and missing quantity

Different types of compounding in steam turbines

What a ramjet engine is

These short questions ensure the student understands key thermodynamic concepts used throughout steam and gas power systems.

SECTION – B (Descriptive / Numerical Questions, Any 5 × 10 = 50 Marks)

This section requires detailed explanations, cycle analysis, sketches, and multi-step numerical computation. Major topics include:

1. Gas Turbine Cycle Modifications

Students describe gas turbine cycles with:

Intercooling

Reheat + Regeneration

Reheat + Intercooling

2. Choked Flow & Nozzle Friction

Explanation of choked flow, Mach number effects, and how friction alters nozzle performance.

3. Steam Engine Indicator Diagrams

(i) Hypothetical vs Actual indicator diagrams
(ii) Meaning of the diagram factor
Also re-explanation of saturation curve & missing quantity

4. Rankine Cycle with Reheat — Numerical Problem

Steam conditions:

HP turbine inlet: 20 MPa, 500°C                  LP turbine exit: 90% dryness

Condenser pressure: 0.005 MPa                  Reheat to 500°C

Students calculate:                                        Pressure after HP turbine

Thermal efficiency of the complete cycle

5. Babcock & Wilcox Boiler

Explanation with neat labelled sketch.

6. Natural Draught Chimney Numerical

Given:

Chimney height: 60 m                                Flue gas temp = 300°C

Ambient air temp = 17°C                           Draught gas cp = 1.0032 kJ/kg·K

Air requirement: 19 kg/kg fuel                   Hot gas exit temp with artificial draught: 150°C

Calorific value = 32604 kJ/kg

Students compute:
(i) Draught (mm of water)
(ii) Chimney efficiency
(iii) Extra heat carried away by flue gases

7. Combustion Analysis Problem

1 kg of C₈H₁₈ with 13 kg of air → compute % CO₂ in dry exhaust gas.

8. Steam Nozzle Flow

Expansion from 16 bar → 5 bar, T = 300°C, ṁ = 1 kg/s
Find throat & exit areas for:
(i) Frictionless expansion
(ii) 10% friction loss

SECTION – C (Long Analytical Problems, Any 2 × 15 = 30 Marks)

This section contains higher-order thermodynamic analysis and velocity diagram problems.

Q3 – Ideal Rankine Cycle (100 MW Plant)

Given:

Turbine inlet: 8 MPa, saturated vapour       Condenser exit: 0.008 MPa, saturated liquid

Net power: 100 MW                                       Students must compute:

Thermal efficiency                                          Back work ratio

Mass flow rate of steam (kg/h)

Q4 – Jet Propulsion + Impulse Turbine Numerical

(a) Principles of:

Jet propulsion                                           Turbojet engine

Turboprop engine                                     Rocket propulsion

(b) One-stage impulse turbine:

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 = inlet angle – 3°         Students determine:

Blade inlet & outlet angles

Power developed

Q5 – Impulse Turbine with Velocity Diagram

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

Inlet velocity = 50 m/s                              Students must determine:

(i) Blade angles for smooth entry and axial exit
(ii) Blade efficiency
(iii) Power output (kW)
(iv) Axial thrust

This requires detailed velocity triangles and thermodynamics.