Diesel Surrogate Fuels for Engine Testing and Chemical-Kinetic Modeling: Compositions and Properties

Abstract

The primary objectives of this work were to formulate, blend, and characterize a set of four ultralow-sulfur diesel surrogate fuels in quantities sufficient to enable their study in single-cylinder-engine and combustion-vessel experiments. The surrogate fuels feature increasing levels of compositional accuracy (i.e., increasing exactness in matching hydrocarbon structural characteristics) relative to the single target diesel fuel upon which the surrogate fuels are based. This approach was taken to assist in determining the minimum level of surrogate-fuel compositional accuracy that is required to adequately emulate the performance characteristics of the target fuel under different combustion modes. For each of the four surrogate fuels, an approximately 30 L batch was blended, and a number of the physical and chemical properties were measured. This work documents the surrogate-fuel creation process and the results of the property measurements.

Preliminary models for viscosity, thermal conductivity, and surface tension of pure fluid constituents of selected diesel surrogate fuels

“…2 (2,2) 16πσ Ω where the dilute gas viscosity is η*, m is the molecular mass, k B is the Boltzmann constant, and T is the absolute temperature. We will further assume that a Lennard-Jones 12-6 potential applies, and use the Lennard-Jones collision diameter for σ. Neufeld et al (14) gave the following empirical correlation for the calculation of the collision integral Ω …”

“…The thermodynamic properties including density, heat capacity, and enthalpy were presented previously (2,3). Here in Tables 7-10 we present the density, viscosity, thermal conductivity, and surface tension of the surrogates along the bubble-point line.…”

“…There are very limited data for comparison. We do not have experimental thermal conductivity data, but Mueller et al (2,3) reported values for kinematic viscosity and surface tension for the four surrogates. Comparisons of the model calculations with the available data are shown in Table 11.…”

“…The surrogates ranged from a simple 4-component mixture to a 9 component mixture. The compositions of these surrogates (2,3) are shown in Table 1. Details on the properties of these surrogates were presented by Mueller et al (2,3); however, the viscosity, thermal conductivity, and surface tension of the surrogate models were not given.…”

“…The compositions of these surrogates (2,3) are shown in Table 1. Details on the properties of these surrogates were presented by Mueller et al (2,3); however, the viscosity, thermal conductivity, and surface tension of the surrogate models were not given. In this work, we present the details of the surrogates and data used to develop correlations for the viscosity, thermal conductivity, and surface tension of the pure fluids constituents of the four surrogates, and these properties for the 4 surrogate mixtures computed along the bubble point.…”