Surrogate Generation and Evaluation for Diesel Fuel

Abstract

The correct representation of a fuel, in terms of its physical and chemical properties and its combustion kinetics poses, a challenge to modern engine development when state-of-the-art simulation technology is used. In this context, a promising approach is the use of surrogates that emulate the properties of real fuels, where the surrogates are made up of a significantly lower number of components than the original fuels. The goal of this paper is to present an algorithm that can be used to generate surrogates composed of real chemical components, as opposed to pseudo components.The algorithm was developed by simultaneously fitting the True Boiling Point (TBP) curve, the liquid density at 15 ℃ and the cetane number. To illustrate the algorithm, surrogates for four different fuels were generated: a commercially available European diesel and three research diesel proposed by the FACE (Fuels for Advanced Combustion Engines) CRC Research Group. Two of the resulting surrogates were produced on a lab-scale and subjected to laboratory examination. For validation, the experimental data for these two surrogates were compared to those for the target fuels and to data generated by thermodynamic models on the basis of the surrogates' compositions.Both the fitted properties and additional properties, which were not used for fitting, were compared with experimental properties such as the ASTM D86 boiling curve, content of aromatics, flash point, heating value, cloud point, viscosity, and tempera-

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

“…In contrast to the ADC method, the D2887 method yields plateau regions that correspond to individual palette compounds, giving the D2887 distillation profiles a stair-step shape for the surrogates (also see, e.g., Figures 6 and 7 of Reiter et al 4 ). The PCERs in Figure 9 and Supporting Information Figure S9 provide additional valuable information regarding when each palette compound elutes as the D2887 procedure is conducted.…”

Integration of computational modeling and experimental techniques to design fuel surrogates

“…In general, a surrogate fuel is one that is composed of a small and diverse number of organic compounds that mimic certain target characteristics of the original fuel (Pitz et al 2007). Since simulations are frequently performed during modern engine testing and fuel combustion, the simpler composition of the surrogate fuels allow for more efficient simulations (Reiter et al, 2015). Surrogate fuels not only provide a better understanding of the effects of the composition on different desired/undesired properties but also have value as time-invariant reference fuels for experimental studies.…”

Optimization of formulation for surrogate fuels for diesel–biodiesel mixtures

“…In comparison with our results, we obtained the n-eicosane instead of n-hexadecane and as shown in the palette (Table 1), the n-hexadecane and n-eicosane as alkanes have similar properties with high cetane number and moderate viscosity and density. The three components obtained in the present work were validated by several previous works as components of optimized surrogates [6,21,28,32,33,36].…”

“…The CN was chosen as the surrogate design property to quantify the ignition efficiency, and it was determined according to the procedure outlined in ASTM D6890. In the regression model, the CN of a mixture was considered to be equal to the sum of the volume fraction weighted CNs of all the components [6,33,44] according to the following expression:…”