Introduction to Thermodynamics and Properties

Flashcards covering the fundamental properties, equilibrium concepts, temperature scales, pressure definitions, and unit systems discussed in the lecture notes.

Extensive Properties

Properties that depend on the extent or size of the system, such as total volume ($V$) or mass ($m$).

Intensive Properties

Properties that are independent of system size and whose values may vary in time and space within the system.

Specific Volume ($v$)

An intensive property defined as the volume per unit mass, calculated as $v = \frac{V}{m}$. It is the reciprocal of density ($\rho$).

Density ($\rho$)

An intensive property defined as mass per unit volume, or $\rho = \frac{m}{V}$. It is commonly used in fluid mechanics.

Zeroth Law of Thermodynamics

A law stating that if two objects are in thermal equilibrium with a third object, the first two objects must be in thermal equilibrium with each other.

Thermal Equilibrium

A state where temperature is uniform (no changes over space) and constant (no changes over time).

Thermodynamic Equilibrium

A more comprehensive type of equilibrium where all properties are uniform and constant throughout the system.

Absolute Temperature Scales

Temperature scales based on thermodynamic principles where the minimum value is zero, including Kelvin ($K$) and Rankine ($^{\circ}R$).

Kelvin ($K$) Conversion

The additive offset used to convert Celsius to Kelvin, defined as $[K] = [^{\circ}C] + 273.15$.

Rankine ($^{\circ}R$) Conversion

The additive offset used to convert Fahrenheit to Rankine, defined as $[^{\circ}R] = [^{\circ}F] + 459.67$.

Pressure ($P$)

An intensive property and scalar quantity defined as $P = \lim_{A \rightarrow A'} (\frac{F}{A})$, where $A'$ is the smallest area for which the molecular nature of matter can be ignored.

Continuum Assumption

The assumption that allows for the molecular nature of matter to be ignored, treating a "point" as the smallest volume that still yields statistically stable properties.

Absolute Pressure

A pressure measurement relative to a perfect vacuum, where the minimum value is $0$. All pressure values in the course are assumed to be absolute unless specified otherwise.

Gage Pressure

The pressure difference between the system and local surroundings, calculated as the absolute pressure minus the local atmospheric pressure.

Standard Atmosphere

A defined value of atmospheric pressure equal to $14.696\,lbf/in^2$, $1.01325\,bar$, or $1.01325 \times 10^5\,Pa$.

Pascal ($Pa$)

The SI unit of pressure, defined as $1\,N/m^2$.

Primary Dimensions

Fundamental physical quantities, such as length, time, and temperature, that are used to create secondary dimensions.

Secondary Dimensions

Dimensions such as area ($[L^2]$), volume ($[L^3]$), or velocity ($[L/t]$) that are combinations of primary dimensions.

$$g_c$$

A constant of proportionality used to map one set of dimensions to another, such as in English Engineering where mass and force are both treated as primary dimensions ($g_c = 32.174\,\frac{lbm \cdot ft}{lbf \cdot s^2}$).

British Gravitational Unit System

A unit system where force is a primary dimension and mass is secondary, using the slug as the unit of mass ($1\,slug = 32.2\,lbm$).