CUBA keys for thermodynamic variables

[kemattil]

The following CUBA keys should be included in order to support modelling of thermal, compressible, and multiphase flows:

SPEED_OF_SOUND: definition: speed of a sound wave as it propagates through an elastic medium shape: [1] type: double

SHEAR_MODULUS: definition: ratio of shear stress to the shear strain shape: [1] type: double

BULK_MODULUS: definition: measure for the compressibility of a substance shape: [1] type: double

HEAT_CAPACITY_V: definition: amount of heat needed to raise the system's temperature by a unit degree as the volume is held constant shape: [1] type: double

HEAT_CAPACITY_P: definition: amount of heat needed to raise the system's temperature by a unit degree as the pressure is held constant shape: [1] type: double

SPECIFIC_HEAT_CAPACITY_V: definition: heat required to raise the temperature of a unit mass of the substance by a unit degree as the volume is held constant shape: [1] type: double

SPECIFIC_HEAT_CAPACITY_P: definition: heat required to raise the temperature of a unit mass of the substance by a unit degree as the pressure is held constant shape: [1] type: double

HEAT_CAPACITY_RATIO: definition: ratio of the heat capacity at constant pressure to heat capacity at constant volume (aka ratio of specific heats). shape: [1] type: double

SPECIFIC_INTERNAL_ENERGY: definition: internal energy per unit mass shape: [1] type: double

THERMAL_CONDUCTIVITY: definition: property of a material to conduct heat shape: [1] type: double

THERMAL_DIFFUSIVITY: definition: rate of transfer of heat in a material (measure of thermal inertia in a sense) shape: [1] type: double

NUMBER_DENSITY: definition: Concentration of countable objects in physical space shape: [1] type: double

MOLECULAR_MASS: definition: Mass of a molecule shape: [1] type: double

MOLAR_MASS: definition: Mass of a substance divided by the amount of substance shape: [1] type: double

MOLAR_VOLUME: definition: Volume occupied by one mole of a substance (at a given temperature and pressure) shape: [1] type: double

SPECIFIC_VOLUME: definition: Ratio of the substance's volume to its mass (reciprocal of density) shape: [1] type: double

COMPRESSIBILITY_FACTOR: definition: Ratio between the molar volumes of a gas and an ideal gas (at a given temperature and pressure) shape: [1] type: double

CRITICAL_TEMPERATURE: definition: Temperature at the critical point shape: [1] type: double

CRITICAL_PRESSURE: definition: Pressure at the critical point shape: [1] type: double

CRITICAL_DENSITY: definition: Density at the critical point shape: [1] type: double

CRITICAL_NUMBER_DENSITY: definition: Number density at the critical point shape: [1] type: double

CRITICAL_MOLAR_VOLUME: definition: Molar volume at the critical point shape: [1] type: double

CRITICAL_SPECIFIC_VOLUME: definition: Specific volume at the critical point shape: [1] type: double

CRITICAL_COMPRESSIBILITY_FACTOR: definition: Compressibility factor at the critical point shape: [1] type: double

REDUCED_TEMPERATURE: definition: Actual temperature divided by the critical temperature shape: [1] type: double

REDUCED_PRESSURE: definition: Actual pressure divided by the critical pressure shape: [1] type: double

REDUCED_DENSITY: definition: Actual density divided by the critical density shape: [1] type: double

REDUCED_NUMBER_DENSITY: definition: Actual number density divided by the critical number density shape: [1] type: double

REDUCED_MOLAR_VOLUME: definition: Actual molar volume divided by the critical molar volume shape: [1] type: double

REDUCED_SPECIFIC_VOLUME: definition: Actual specific volume divided by the critical specific volume shape: [1] type: double

REDUCED_COMPRESSIBILITY_FACTOR: definition: Actual compressibility factor divided by the critical compressibility factor shape: [1] type: double

ACENTRIC_FACTOR: definition: Measure of the non-sphericity (centricity) of molecules shape: [1] type: double

[ahashibon]

looks good to me (please also see discussion about the CRITICAL prefix on slack)

[stefanoborini]

Copied here for reference. Please let's try to keep one point of information.

adham [6:28 PM]
@kemattil issue 76 clarifies the CRITICAL_ prefix, but I think in general, we should be specific about the equation used, so the description should show a link to a reference showing the equation it self using the best metadata known to mankind (i.e., maths!). Perhaps for now we can use LaTex to write the euqation in the definition using the CUBA variables? what do you think (our plan is to have in the future URIs to docs).

[kemattil]

Providing a mathematical definition for a CUBA variable (when appropriate, i.e. optional), using e.g. latex, sounds like a very good idea.

The idea could perhaps be taken further by requiring a (latex) symbol per CUBA variable, but this might be too much: it is difficult to avoid symbol conflicts with a large (and diverse) set of CUBA variables ...