Thermodynamic Flashcards
What is an Ideal Gas?
A hypothetical gas composed of a large number of randomly moving particles not subject to intermolecular forces, following the ideal gas law under all conditions of temperature and pressure.
What is meant by the term ‘Critical Temperature’ of steam?
The maximum temperature at which water can exist as a liquid regardless of the pressure applied, above which it becomes a supercritical fluid (374°C for water).
What is a Perfect Gas?
A theoretical gas that obeys the ideal gas law and has constant specific heat capacities, not condensing or liquefying under cooling or compression.
State Boyle’s Law.
For a fixed amount of gas at constant temperature, the pressure is inversely proportional to its volume. P ∝ 1/V or PV = constant.
State Charles’ Law.
The volume of a given mass of gas is directly proportional to its temperature at constant pressure. V ∝ T or V/T = constant.
State the combined gas law equation.
(P1V1)/T1 = (P2V2)/T2, where P is pressure, V is volume, and T is temperature.
What is the latent heat of fusion?
The amount of heat required to change 1 kg of a solid into a liquid at constant temperature.
What is the latent heat of evaporation?
The amount of heat required to change 1 kg of a liquid into vapor at constant temperature.
Sketch and explain the Otto cycle.
The idealized thermodynamic cycle for spark-ignition internal combustion engines consisting of four processes: 1–2: Isentropic compression, 2–3: Constant-volume heat addition, 3–4: Isentropic expansion, 4–1: Constant-volume heat rejection.
Sketch and explain the Brayton cycle.
The thermodynamic cycle for gas turbines consisting of four processes: 1–2: Isentropic compression, 2–3: Constant-pressure heat addition, 3–4: Isentropic expansion, 4–1: Constant-pressure heat rejection.
Sketch and explain the Dual cycle.
Combines features of both the Otto and Diesel cycles with heat addition partly at constant volume and partly at constant pressure. It consists of five processes: 1–2: Isentropic compression, 2–3: Constant-volume heat addition, 3–4: Constant-pressure heat addition, 4–5: Isentropic expansion, 5–1: Constant-volume heat rejection.
Sketch and explain the Joule cycle.
The ideal gas turbine cycle consisting of four processes similar to the Brayton cycle.
