Prandtl number (Pr) is dimensionless ratio of momentum to thermal diffusivity. Formula: Pr = μ cp / k, where μ is viscosity, cp is specific heat, k is thermal conductivity
Steady flow control volume equations apply only to control surface quantities. Perfect gas properties depend only on temperature (P=pRT, u=u(T)). Specific heats (cp, cv) can be functions of temperature
Boiling is rapid liquid-to-gas phase transition at 100°C. Two main types: nucleate boiling with bubbles and critical heat flux boiling. Boiling point decreases with altitude due to lower atmospheric pressure
Evaporator uses heat transfer to facilitate liquid-to-vapor phase transition. Circulating liquid is exposed to reduced pressure environment. Main components include tubes, fins, heat source, and vapor distillation
Superheated steam is steam above its vaporization point at the measurement pressure. Can cool without changing state to saturated vapor-liquid mixture. Produced by passing saturated steam through separate heating device
Thermal radiation is electromagnetic energy emitted by matter above absolute zero. Most radiation at room temperature is in infrared spectrum. Above 525°C, matter becomes visible through incandescence. Thermal radiation is one of three main heat transfer mechanisms