**VOLEXPCOEF**

The VOLEXPCOEF function returns the volumetric coefficient of thermal expansion for the specified fluid and conditions. This coefficient is defined by the following relation:

b = -(1/r) dr/dT (at constant P)

where

b is the volumetric coefficient of thermal expansion in units of 1/K (SI) or 1/R (English)

r is the density of the fluid

dr/dT is the derivative of density with respect to temperature at fixed pressure

For an ideal gas fluid, b evaluates to 1/T where T is the temperature in K or R.

The VOLEXPCOEF function for real fluids and ideal gases will accept any appropriate set of inputs. In general, any combination of inputs that are sufficient to determine density will be accepted. For incompressible substances, temperature must be the only input.

Examples:

$UnitSystem SI C kPa mass

R$='Steam'

beta=VOLEXPCOEF (R$,T=100 [C],P=101.3 [kPa])

beta_Cu=VOLEXPCOEF(COPPER,T=100 [C])

{Solution:

beta=0.002884 [1/K]

beta_Cu=0.00005177 [1/K]

}

Also see: LinearExpCoef

Return to Thermophysical Functions