Thermodynamics and Heat Transfer
Thermodynamics tracks energy and its transformations; heat transfer describes how thermal energy moves. Together they cover engines, refrigeration, and thermal systems using the first and second laws.
Laws and Energy Balances
The first law is conservation of energy: for a closed system, the change in internal energy equals heat added minus work done. Sensible heating follows Q = m·c·(delta T). Energy balances on control volumes underpin most system analysis.
The Second Law and Efficiency
The second law limits how much heat can become work. A reversible Carnot engine between absolute temperatures T_hot and T_cold has efficiency eta = 1 - T_cold/T_hot, the ceiling no real engine can beat. Entropy always increases in real processes.
Heat Transfer Modes
Heat moves by conduction (Fourier's law, Q = k·A·(delta T)/L), convection (Q = h·A·(delta T)), and radiation (proportional to absolute temperature to the fourth power). Ideal-gas behavior (P·V = n·R·T) links pressure, volume, and temperature in gas processes.