7.6.4.2.25. Ideal_Gas

Syntax: Density [{of} SpeciesName] = Ideal_Gas [P_Ref = p_ref | T_Ref = t_ref | R = r]
Scope: Aria Material
Summary: Ideal gas density
Description: $\rho = \frac{(P_\text{ref} + P) \mathit{MW}_\text{mix}}{R (T_\text{ref} + T}$

where $P_\text{ref}$ and $T_\text{ref}$ are reference pressure and temperatures, respectively. $T$ is temperature, $P$ is pressure, $\mathit{MW}_\text{mix}$ is the mixture molecular weight, $R$ the provided gas constant. In this model $\mathit{MW}_\text{mix} = \sum_{i=0}^n Y_i \mathit{MW}_\text{i}$ where $Y_i$ and $\mathit{MW}_\text{i}$ are the species mass fraction and molecular weights, respectively for $n$ species.