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Search Publications by: Ian Bell (Fed)

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Displaying 26 - 50 of 78

Dynamic Crossover in Fluids: From Hard Spheres to Molecules

July 7, 2021
Author(s)
Ian Bell, Stephanie Delage-Santacreu, Hai Hoang, Guillaume Galliero
We propose a simple and generic definition of a demarcation reconciling structural and dynamic frameworks when combined with the entropy scaling framework. This crossover line between gas- and liquid-like behaviors is defined as the curve for which an

Super-Ancillary Equations for Cubic Equations of State

June 29, 2021
Author(s)
Ian Bell, Ulrich K. Deiters
Calculation of thermodynamic phase equilibrium is error-prone and can fail both near the critical point and at very low temperatures because of the limited precision available in double precision arithmetic. Most importantly, these calculations frequently

Survey of Data and Models for Refrigerant Mixtures Containing Halogenated Olefins

June 1, 2021
Author(s)
Ian Bell, Demian Riccardi, Ala Bazyleva, Mark O. McLinden
We survey existing data for refrigerant blends containing halogenated olefins (hydrofluoroolefins (HFO), hydrochlorofluoroolefins (HCFO), and hydrochloroolefins (HCO)) in the open literature. The data are primarily taken from the NIST SOURCE database and

Unphysical critical curves of binary mixtures predicted with GERG models

October 19, 2020
Author(s)
Ian H. Bell, Ulrich K. Deiters
When applied to asymmetric binary mixtures (e.g., methane + pentane or heavier alkanes, hydrogen-containing mixtures), the GERG equation of state (GERG-2004 or GERG-2008) predicts critical curves with physically unreasonable temperature maxima above the

Differential equations for critical curves of fluid mixtures

September 22, 2020
Author(s)
Ian Bell, Ulrich K. Deiters
A novel, particularly robust method for the calculation of critical curves of fluid mixtures is proposed that makes use of differential equations representing the critical conditions (isochoric thermodynamics formalism). These differential equations are

Quasiuniversal Excess Entropy Scaling in Binary Supercooled Liquids

August 27, 2020
Author(s)
Ian H. Bell, Jeppe Dyre, Trond Ingebrigtsen
Transport coefficients, such as viscosity or diffusion coefficient, show significant dependence on density or temperature near the glass transition. Although several theories have been proposed for explaining this dynamical slowdown, the origin remains to

The Status of Thermodynamic Data and Models for CF3I and its Mixtures

July 24, 2020
Author(s)
Ian H. Bell, Mark O. McLinden
There is a renewed interest in the use of the refrigerant CF3I for refrigeration and air conditioning applications, driven by its low global warming potential (equivalent to CO2), and very low (but nonzero) ozone depletion potential. In this paper we will

Entropy Scaling of Viscosity – I: A Case Study of Propane

May 12, 2020
Author(s)
Ian H. Bell
In this work a broadly-applicable and simple approach for developing high accuracy viscosity correlations yielding uncertainties approximately equal to the uncertainties of the underlying data is presented. The approach is based on the combination of a

An Entropy Scaling Demarcation of Gas- and Liquid-like Fluid Behaviors

April 1, 2020
Author(s)
Ian H. Bell, Guillaume Galliero, Stephanie Delage-Santacreu, Lorenzo Costigliola
In this work we propose a generic and simple definition of a line separating gas-like and liquid-like fluid behaviors in the supercritical region. We argue that this line is defined by the location of the minimum of the macroscopically scaled viscosity

A Benchmark Open-Source Implementation of COSMO-SAC

February 14, 2020
Author(s)
Ian H. Bell, Erik Mickoleit, Chieh-Ming Hsieh, Shiang-Tai Lin, Jadran Vrabec, Cornelia Breitkopf, Andreas J?ger
The COSMO-SAC modeling approach has found wide application in a range of industries due to its good predictive capabilities. While UNIFAC is in general more accurate than COSMO-SAC, the UNIFAC model contains many adjustable parameters and cannot be used if

Covariance-based uncertainty analysis of reference equations of state

January 6, 2020
Author(s)
Howard Cheung, Jerome Frutiger, Ian Bell, Jens Abildskov, Gurkan Sin, Shengwei Wang
This work presents a detailed methodology for uncertainty analysis applied to a reference equation of state (EOS) based on Helmholtz energy. With increasing interest in uncertainties of thermal process models, it is important to quantify the property

Options for Low-GWP Refrigerants

November 6, 2019
Author(s)
Mark O. McLinden, Andrei F. Kazakov, J S. Brown, Riccardo Brignoli, Ian H. Bell, Piotr A. Domanski
We summarize a systematic examination of possible low-GWP (global warming potential) replacements for the HFC (hydrofluorocarbon) refrigerants currently used in small air-conditioning systems. The methodology identified the optimal thermodynamic parameters

The hunt for refrigerant blends to replace R-134a

August 1, 2019
Author(s)
Ian H. Bell, Piotr A. Domanski, Gregory T. Linteris, Mark O. McLinden
We investigated refrigerant blends as possible low GWP (global warming potential) alternatives for R-134a in an air-conditioning application. We carried out an extensive screening of the binary, ternary, and four-component blends possible among a list of