Multiparameter Equations of State for Selected Siloxanes

Published

April 25, 2006

Author(s)

P. Colonna, R. Nannan, A. Guardone, Eric Lemmon

Abstract

The development of technical equations of state using the 12-parameter Span-Wagner functional form for four siloxanes is presented in two parts. The fluids under investigation include hexamethyldisiloxane (MM), tetradecamethylhexasiloxane (MD4M), octamethylcyclotetrasiloxane (D4), and decamethylcyclopentasiloxane (D5). Siloxanes are used as heat transfer fluids and working media in energy conversion applications. In part I, available properties are critically evaluated and selected for the optimization of the equation of state parameters. Due to the insufficient number of available measurements, several other properties are estimated with the most accurate ad hoc methods. These estimates are then used in the optimization of the equation of state (EoS) parameters. Moreover, experimental saturated liquid density and vapor pressure data are correlated with the equations proposed by Daubert and Wagner-Ambrose, respectively, to provide short, simple and accurate equations for the computation of these properties. The performance of the mentioned equations of state is illustrated in the second part of this article.

Citation

Fluid Phase Equilibria

Volume

244

Pub Type

Journals

Download Paper

Local Download

Keywords

Caloric Properties, Critical Point, D4, D5, Density, Equation of State, Fundamental Equation, MD4M, MM, Siloxane, Thermodynamic Properties, Vapor Pressure

Citation

Colonna, P. , Nannan, R. , Guardone, A. and Lemmon, E. (2006), Multiparameter Equations of State for Selected Siloxanes, Fluid Phase Equilibria, [online], https://tsapps.nist.gov/publication/get_pdf.cfm?pub_id=50279 (Accessed October 11, 2025)