(SEM IV) THEORY EXAMINATION 2017-18 APPLIED THERMODYNAMICS

APPLIED THERMODYNAMICS – B.Tech (Semester IV), RME-403

This is a 3-hour, 70-mark theory examination aimed at testing a student’s understanding of thermodynamic cycles, I.C. engines, steam power plants, gas turbines, boilers, condensers, nozzles, and turbine performance.

The paper consists of three structured sections, covering conceptual theory, numerical problem solving, and cycle/diagram-based explanations.
 

SECTION A — Short Conceptual Questions (2 × 7 = 14 Marks)

This section asks 7 brief questions to test fundamental thermodynamic knowledge.

Topics include:

Otto cycle vs Diesel cycle                   Cogeneration in steam power plants

Characteristics of good fuel               Equivalent evaporation for boiler comparison

Degree of reaction & state point locus (turbines)       Enthalpy of formation

Gas turbine vs I.C. engine

These questions test definitions, basic concepts, and quick comparisons.
 

SECTION B — Descriptive & Numerical Questions (7 × 3 = 21 Marks)

Attempt any 3 out of 5.
This section includes major numericals, working principles, and explanations.

Questions cover:

(a) A full performance trial of a 2-stroke oil engine:

Indicated power                           Brake power

Mechanical efficiency                   Brake thermal efficiency

Heat balance sheet (major numerical)

(b) Orsat apparatus:

Working & sketch

Air–fuel ratio for C₃H₈ with 150% theoretical air

(c) Steam impulse turbine:

Working principle                        Need for compounding

Pressure-velocity compounding diagram

(d) Mass flow of flue gases through chimney using draught equation

(e) Steam nozzle:

Definition

Derivations for velocity of steam & discharge

This section tests problem-solving skills + real plant/device understanding.
 

SECTION C — Long Answer / Advanced Numerical Questions (7 marks each)

Q3 – Cycles (Carnot, Brayton, Diesel)

Derivation of efficiency expressions for Carnot & Brayton cycles
OR

Numerical for air-standard diesel cycle: thermal efficiency, net work, MEP

Q4 – Boiler & Rankine Cycle Calculations

Boiler conversion from coal to oil: calorific value, thermal efficiency, equivalent oil mass
OR

Rankine cycle working between 28 bar & 0.06 bar: dryness fraction, efficiency, work ratio, SSC

Q5 – Impulse Turbine (Blade Efficiency & Performance)

Deriving maximum blade efficiency ηₘₐₓ = cos²α
OR

Numerical: blade angles, axial thrust, power, blade efficiency, stage efficiency

Q6 – Boilers & Condenser Calculations

Essentials of a good boiler; fire-tube vs water-tube; sketch of Babcock & Wilcox boiler
OR

Numerical: condenser vacuum, vacuum efficiency, condenser efficiency

Q7 – Gas Turbines & Jet Propulsion

Two-stage compressor plant with intercooler → net power (with given limits)
OR

Principle of jet propulsion, classification, and working of turbo-jet engine with sketch

This section tests cycle analysis, turbine theory, boiler/condenser performance, and high-level thermodynamic reasoning.
 

OVERALL PURPOSE OF THE EXAM

The examination evaluates whether the student can:

Analyze thermodynamic cycles (Otto, Diesel, Brayton, Rankine)

Solve engine performance calculations

Understand boiler performance, fuel characteristics & steam properties

Interpret turbine mechanics (impulse & reaction)

Perform nozzle, condenser & chimney calculations

Understand gas turbine working & jet propulsion principles

Apply steam tables & Mollier chart effectively

It combines theory, diagrams, practical engineering systems, and strong numerical skills essential for mechanical engineering fields.