Thermodynamics (Symbols)
========================

Symbols related to thermodynamics.

.. py:currentmodule:: symplyphysics.symbols.thermodynamics

.. py:data:: temperature

    Temperature is a scalar quantity that quantitatively expresses the attribute of hotness and coldness. It reflects
    the average kinetic energy of the vibrating and colliding atoms making up a substance.

Symbol:
    :code:`T`

Latex:
    :math:`T`

Dimension:
    :code:`temperature`


.. py:data:: adiabatic_index

    **Adiabatic index**, or **heat capacity ratio**, is the ratio of heat capacity at constant pressure to that
    at constant volume.

Symbol:
    :code:`gamma`

Latex:
    :math:`\gamma`

Dimension:
    :code:`dimensionless`


.. py:data:: heat_capacity

    **Heat capacity** or **thermal capacity** is a physical property of matter, defined as the amount of heat to be
    supplied to an object to produce a unit change in its temperature.

Symbol:
    :code:`C`

Latex:
    :math:`C`

Dimension:
    :code:`energy/temperature`


.. py:data:: molar_heat_capacity

    **Molar heat capacity** is defined as the heat capacity per unit amount of substance.

Symbol:
    :code:`c_m`

Latex:
    :math:`c_{m}`

Dimension:
    :code:`energy/(amount_of_substance*temperature)`


.. py:data:: thermal_expansion_coefficient

    **Thermal expansion coefficient** describes how the size of an object changes with a change in temperature at
    constant pressure.

Symbol:
    :code:`alpha`

Latex:
    :math:`\alpha`

Dimension:
    :code:`1/temperature`


.. py:data:: thermodynamic_compressibility

    **Compressibility** is a measure of the instantaneous relative volume change of a fluid or solid as a response
    to a pressure or mean stress change.

Symbol:
    :code:`beta`

Latex:
    :math:`\beta`

Dimension:
    :code:`1/pressure`


.. py:data:: thermal_resistance

    **Thermal resistance** measures the opposition to the heat current in a material or system.

Symbol:
    :code:`R`

Latex:
    :math:`R`

Dimension:
    :code:`temperature/power`


.. py:data:: thermal_conductivity

    **Thermal conductivity** of a material is a measure of its ability to conduct heat. It is defined as the
    proportionality coefficient between the heat flux and the temperature gradient.

Symbol:
    :code:`k`

Latex:
    :math:`k`

Dimension:
    :code:`power/(length*temperature)`


.. py:data:: thermal_insulance

    The **R-value**, or **thermal insulance**, is a measure of how well a two-dimensional barrier, such as a layer of
    insulation, a window or a complete wall or ceiling, resists the conductive flow of heat, in the context of construction.

Symbol:
    :code:`R_val`

Latex:
    :math:`R_\text{val}`

Dimension:
    :code:`area*temperature/power`


.. py:data:: compressibility_factor

    The **compressibility factor**, also known as the **compression factor** or the **gas deviation factor**,
    describes the deviation of a real gas from ideal gas behavior.

Symbol:
    :code:`Z`

Latex:
    :math:`Z`

Dimension:
    :code:`dimensionless`


.. py:data:: partition_function

    In statistical mechanics, the **partition function** describes the statistical properties of a system in
    thermodynamic equilibrium. It plays the role of a normalization constant in microstate distributions of
    the system by encoding the information about how the probabilities are partitioned among the different
    microstates based on the specific microstate variables.

Symbol:
    :code:`Z`

Latex:
    :math:`Z`

Dimension:
    :code:`dimensionless`


.. py:data:: boltzmann_factor

    In statistical mechanics, the **Boltzmann factor** is a quantity that describes the approximate fraction
    of particles in the canonical ensemble.

Symbol:
    :code:`f`

Latex:
    :math:`f`

Dimension:
    :code:`dimensionless`


.. py:data:: entropy

    **Entropy** is a physical quantity most commonly associated with a state of randomness or disorder. In the
    approach of the classical thermodynamics, entropy is defined in terms of macroscopically measurable physical
    properties, such as volume, bulk mass, pressure, etc. The statistical definition defines it in terms of the
    statistics of the motions of the microscopic constituents of a system.

Symbol:
    :code:`S`

Latex:
    :math:`S`

Dimension:
    :code:`energy/temperature`


.. py:data:: chemical_potential

    The **chemical potential** of a species is the energy that can be absorbed or released due to a change of the
    particle number of the given species, e.g. in a chemical reaction or phase transition.

Symbol:
    :code:`mu`

Latex:
    :math:`\mu`

Dimension:
    :code:`energy`


.. py:data:: gibbs_energy

    The **Gibbs energy** is a thermodynamic potential that can be used to calculate the maximum amount of work,
    other than pressure-volume work, that may be performed by a thermodynamically closed system at constant
    temperature and pressure.

Symbol:
    :code:`G`

Latex:
    :math:`G`

Dimension:
    :code:`energy`


.. py:data:: enthalpy

    **Enthalpy** is a state function defined as the sum of a thermodynamic system's internal energy and the
    product of its pressure and volume, used in measurements at a constant external pressure.

Symbol:
    :code:`H`

Latex:
    :math:`H`

Dimension:
    :code:`energy`


.. py:data:: helmholtz_free_energy

    In thermodynamics, the **Helmholtz free energy** (or **Helmholtz energy**) is a thermodynamic potential
    that measures the useful work obtainable from a closed thermodynamic system at a constant temperature.

Symbol:
    :code:`F`

Latex:
    :math:`F`

Dimension:
    :code:`energy`


.. py:data:: internal_energy

    **Internal energy** is a thermodynamical state function which denotes the entire energy of a closed system
    of molecules or the sum of a substance's molecular kinetic and potential energy. It excludes the potential
    and kinetic energies of the system as a whole and is only concerned with the energy of the molecules comprising
    the system.

Symbol:
    :code:`U`

Latex:
    :math:`U`

Dimension:
    :code:`energy`


.. py:data:: thermal_wavelength

    The **thermal de Broglie wavelength** is a quantity that is roughly the average de Broglie wavelength of
    particles in an ideal gas at the specified temperature.

    **Links:**

    #. `Thermal de Broglie wavelength <https://en.wikipedia.org/wiki/Thermal_de_Broglie_wavelength>`__.

Symbol:
    :code:`lambda`

Latex:
    :math:`\lambda`

Dimension:
    :code:`length`


.. py:data:: heat

    In thermodynamics, **heat** is energy in transfer between a thermodynamic system and its surroundings by modes
    other than thermodynamic work and transfer of matter.

Symbol:
    :code:`Q`

Latex:
    :math:`Q`

Dimension:
    :code:`energy`


.. py:data:: thermal_efficiency

    The **thermal efficiency** is a dimensionless performance measure of a device that uses thermal energy. A generic
    definition of thermal energy is the ratio of the energy benefit to the energy costs attributed to the defice.

Symbol:
    :code:`eta`

Latex:
    :math:`\eta`

Dimension:
    :code:`dimensionless`


.. py:data:: statistical_weight

    **Statistical weight**, or **multiplicity**, is a physical quantity denoting the number of microstates
    corresponding to a particular macrostate of a thermodynamic system.

Symbol:
    :code:`Omega`

Latex:
    :math:`\Omega`

Dimension:
    :code:`dimensionless`


.. py:data:: relative_humidity

    **Relative humidity** is a quantity that indicates a present state of absolute humidity relative to a
    maximum humidity given the same temperature.

Symbol:
    :code:`phi`

Latex:
    :math:`\varphi`

Dimension:
    :code:`dimensionless`


.. py:data:: mean_free_path

    **Mean free path** is the average distance over which a moving particle travels before
    substantially changing its direction or energy.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Mean_free_path>`__.

Symbol:
    :code:`lambda`

Latex:
    :math:`\lambda`

Dimension:
    :code:`length`


.. py:data:: sutherland_constant

    The **Sutherland constant** is a parameter used in the Sutherland model for gaseous viscosity.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Temperature_dependence_of_viscosity#Sutherland_model>`__.

Symbol:
    :code:`S`

Latex:
    :math:`S`

Dimension:
    :code:`temperature`


.. py:data:: prandtl_number

    The **Prandtl number** is a dimensionless number defined as the ratio of momentum
    diffusivity to thermal diffusivity.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Prandtl_number>`__.

Symbol:
    :code:`Pr`

Latex:
    :math:`\text{Pr}`

Dimension:
    :code:`dimensionless`


.. py:data:: grashof_number

    The **Grashof number** approximates the ratio of the buoyancy to viscous forces acting
    on a fluid.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Grashof_number>`__.

Symbol:
    :code:`Gr`

Latex:
    :math:`\text{Gr}`

Dimension:
    :code:`dimensionless`


.. py:data:: kinematic_viscosity

    In fluid dynamics, **kinematic viscosity**, or **momentum diffusivity**, is defined as
    the ratio of the dynamic viscosity over the density of the fluid.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Viscosity#Kinematic_viscosity>`__.

Symbol:
    :code:`nu`

Latex:
    :math:`\nu`

Dimension:
    :code:`area/time`


.. py:data:: thermal_diffusivity

    **Thermal diffusivity** is the thermal conductivity divided by density and specific heat
    capacity at constant pressure.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Thermal_diffusivity>`__.

Symbol:
    :code:`alpha`

Latex:
    :math:`\alpha`

Dimension:
    :code:`area/time`


.. py:data:: attractive_forces_parameter

    Parameter specific to each individual substance, usually attributed to the magnitude of
    attractive forces between particles of the system.

Symbol:
    :code:`a`

Latex:
    :math:`a`

Dimension:
    :code:`pressure*volume**2/amount_of_substance**2`


.. py:data:: excluded_volume_parameter

    Parameter specific to each individual substance, usually attributed to the amount of
    excluded molar volume due to a finite size of particles.

Symbol:
    :code:`b`

Latex:
    :math:`b`

Dimension:
    :code:`volume/amount_of_substance`


.. py:data:: heat_transfer_coefficient

    The **heat transfer coefficient** is the proportionality constant between the heat flux
    :math:`d \dot{Q} / d A` and the thermodynamic driving force for the flow of heat
    (i.e. the temperature difference :math:`\Delta T`). In other words, it is the rate of
    heat transfer through a surface of unit area that results in a unit temperature
    difference.

    **Links:**

    #. `Wikipedia <https://en.wikipedia.org/wiki/Heat_transfer_coefficient#>`__.

Symbol:
    :code:`h`

Latex:
    :math:`h`

Dimension:
    :code:`power/(area*temperature)`