About this previous year paper
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.