Thermodynamics

Energy, heat, work — and the rules that limit every engine. The science of energy conversion. Learn properties of substances, the laws of thermodynamics, entropy and enthalpy, heat engines, refrigerators and heat pumps, and the Otto, Diesel, Brayton and Rankine cycles behind cars, jets and power stations.

• Properties — Thermodynamic properties describe the state of a substance. Learn systems and boundaries, pressure, temperature and specific volume, the ideal-gas law, phases and saturation, quality and how to read steam tables.
• Laws of Thermodynamics — The zeroth, first, second and third laws define temperature, energy conservation, the direction of processes and absolute zero. Learn energy balances for closed and open (steady-flow) systems and what the second law forbids.
• Entropy — Entropy measures energy dispersal and irreversibility. Learn ΔS = ∫δQ/T, entropy change of solids, liquids and ideal gases, entropy generation, isentropic processes and isentropic efficiency.
• Enthalpy — Enthalpy h = u + pv is the energy carried by a flowing fluid. Learn why it's used for open systems, sensible and latent heat, c_p Δt calculations, steam enthalpies and heating curves.
• Heat Engines — A heat engine converts heat into work by operating between a hot source and a cold sink. Learn thermal efficiency, the Carnot limit, heat rate, and how real engines — car engines, gas turbines, power plants — compare.
• Refrigeration — Refrigerators and heat pumps move heat from cold to hot using work. Learn COP, the Carnot limit, the vapour-compression cycle (evaporator, compressor, condenser, expansion valve), refrigerants and capacity in tons.
• Thermodynamic Cycles — Ideal cycles model real engines and power plants. Learn the Otto (petrol), Diesel, Brayton (gas turbine) and Rankine (steam) cycles, their P–v behaviour, efficiency formulas and the design levers that improve them.