Pressure, Temperature, and Volume (PVT)

Constant Density

You can specify a simple PVT behavior with a constant density throughout the material.

Input Data	Description
Density	The density value you want to specify throughout the material. If you select this option, the PVT material behavior uses the density value specified as part of the overall material definition.

Modified Tait

The modified two-domain Tait PVT model defines the pressure-volume-temperature relationship as:

where $C=0.0894,$ and $V_t(T,P)$ is the modified term for crystalline material.

If $T\ge T_t(P),$

If $T<T_t(P),$

where $\tilde{T}=T-b_5,$ and $T_t(P)=b_5+b_{6}P,$ .

Input Data	Description
b1l	$b_{1,l}$ , in terms of volume per mass.
b2l	$b_{2,l}$ , in terms of volume per mass per temperature in degrees C.
b3l	$b_{3,l}$ , in terms of force per area.
b4l	$b_{4,l}$ , in terms of temperature in degrees C.
b1s	$b_{1,s}$ , in terms of volume per mass.
b2s	$b_{2,s}$ , in terms of volume per mass per temperature.
b3s	$b_{3,s}$ , in terms of force per area.
b4s	$b_{4,s}$ , in terms of temperature in degrees C.
b5	$b_5$ , in terms of temperature in degrees C.
b6	$b_6$ , in terms of area times temperature (in degrees C) per force.
b7	$b_7$ , in terms of volume per mass.
b8	$b_8$ , per temperature in degrees C.
b9	$b_9$ , in terms of area per force (the reciprocal of pressure).

Spencer Gilmore

The Spencer Gilmore equation of state defines the pressure-volume-temperature relationship as:

where $P$ is the pressure, $T$ is the temperature, $V$ is the volume of unit material mass, and $\hat{R}$ is the gas constant.

Input Data	Description
P0	Pressure, $\pi$ , in terms of force per area.
L0	An experimental constant, $W$ , in terms of volume per mass.
R0	The gas constant, $\hat{R}$ , in terms of energy per weight per temperature (degrees K).