Thermodynamics (ME-302) - Important Questions

Calculate the boundary work done for isothermal / $pV = \text{constant}$ compression or expansion between two pressures.

State the Kelvin-Planck and Clausius statements of the second law of thermodynamics.

Calculate heat transferred and (mean) heat / specific heat capacity from mass, temperature change and heat or $C_n(T)$.

Discuss the Clausius inequality and its role in defining the second law of thermodynamics.

Calculate the minimum power required for a refrigerator operating between given cold and hot reservoir temperatures with a given heat leak rate.

Derive the expression for $Q_4/Q_1$ in terms of $T_1, T_2, T_3, T_4$ for a reversible power cycle taking $Q_1$ at $T_1$ and rejecting $Q_2$ at $T_2$ driving a reversible heat pump abstracting $Q_4$ at $T_4$ and discharging $Q_3$ at $T_3$.

Reversible heat engine driving a reversible refrigerator between three reservoirs: given heat to engine and net work output, find heat absorbed by refrigerator and net heat rejected to the intermediate reservoir.

Apply the non-flow first law $Q = \Delta U + W$ to a closed-system compression/expansion to find heat transfer given change in internal energy and work done.

What is thermodynamics equilibrium? Explain mechanical, chemical and thermal equilibrium.

State the availability function and explain whether it is a property.

What is the Carnot cycle? Derive the expression for its thermal efficiency.

Sketch on a P-V diagram and calculate the net work done for a cycle consisting of constant-volume compression, isothermal expansion and constant-pressure cooling.

Determine steam properties using steam tables: dryness fraction/quality, specific volume, specific enthalpy, specific entropy and specific internal energy for wet, dry saturated and superheated states.

Draw the T-s phase equilibrium diagram for water / pure substance showing wet, saturated and compressed liquid regions and constant property lines.

Explain pure substance and its phases, formation of steam and its thermodynamic properties.

Discuss the measurement and significance of dryness fraction in steam engineering.

Explain with neat sketch the working of the combined separating and throttling calorimeter for determining dryness fraction, including its need/shortcomings of individual methods and methods of finding dryness fraction.

Explain the process of generation / formation of steam at constant pressure with graphical representation.

Explain the PVT (p-V-T) surface of a real gas with a neat sketch.

Calculate heat required to convert feed water at given temperature to wet steam at given pressure and dryness fraction.

Explain the triple point with a neat diagram and explain the p-V-T surface.

Calculate the specific internal energy of superheated steam and its change after expansion to a lower pressure wet state.

Explain sensible heat and latent heat of water and enthalpy of wet steam and superheated steam in steam formation.

Define dryness fraction and entropy of evaporation.

Define the Carnot cycle and its importance, and compare efficiencies of Carnot, Otto, Diesel and Dual cycles.

Discuss the pressure-volume-temperature relationship for mixtures of ideal gases and its importance.

Describe internal energy, enthalpy and specific heat of gas mixtures and explain the significance of Mollier charts in thermodynamic analysis.

Write the expressions for efficiency of Otto and Diesel cycles.

Numerical on ideal constant-volume Otto cycle given pressures, temperatures, compression ratio and heat supplied to find thermal efficiency, maximum temperature, work and mean effective pressure.

Write short notes on any two of: Boyle's law and Charles's law, Kelvin-Planck statement of second law, actual vs theoretical combustion, and Brayton cycle.

Define the enthalpy and internal energy of a system.

For a gas undergoing polytropic compression with given initial and final volumes, pressures and temperature, determine the mass of gas, the polytropic index n, and the heat received or rejected.

What is meant by air standard efficiency of a cycle?

Derive the expression for air-standard efficiency of the Otto cycle.

Derive the expression for air-standard efficiency of the Diesel cycle.

Numerical calculation on ideal air-standard Diesel cycle to find state properties, heat added/rejected and cycle efficiency.

Compare actual and theoretical combustion processes and their effect on engine performance.

Explain the significance of enthalpy of formation and its relation to enthalpy of reaction in thermodynamic systems.

Given liquid/solid fuel ultimate analysis by mass, calculate the stoichiometric air required per kg of fuel and the mass/volumetric composition of gaseous combustion products with excess air.

Write the balanced combustion equation for gasoline as octane and calculate the mass of oxygen required for complete combustion of a given mass.

Write short notes on any three of: basic concept of third law of thermodynamics, first law analysis of reacting systems, use of steam table and Mollier chart, limitations of first law of thermodynamics.

What is adiabatic flame temperature and how is it estimated?

What are primary fuels ? List out some primary fuels and define heating value of fuel.