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    <title>Transport Research International Documentation (TRID)</title>
    <link>https://trid.trb.org/</link>
    <atom:link href="https://trid.trb.org/Record/RSS?s=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" rel="self" type="application/rss+xml" />
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    <language>en-us</language>
    <copyright>Copyright © 2026. National Academy of Sciences. All rights reserved.</copyright>
    <docs>http://blogs.law.harvard.edu/tech/rss</docs>
    <managingEditor>tris-trb@nas.edu (Bill McLeod)</managingEditor>
    <webMaster>tris-trb@nas.edu (Bill McLeod)</webMaster>
    <image>
      <title>Transport Research International Documentation (TRID)</title>
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      <link>https://trid.trb.org/</link>
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    <item>
      <title>Time-Resolved Spray Characterization via Unified Optical Flow and Binarization Technique</title>
      <link>https://trid.trb.org/View/2688756</link>
      <description><![CDATA[This work leverages an unsupervised machine learning and advanced image processing techniques to characterize the breakup of fuel sprays in a small-scale combustor under reacting conditions, providing valuable insights into near-nozzle flow phenomenology. The proposed methodology integrates an improved optical flow model on a convolutional neural network to extract flow vectors with a binarization technique to assess droplets’ size and shape across the region of interest. The velocimetry approach demonstrates superior performance compared to a state-of-the-art optical flow model when applied to high-speed X-ray phase contrast spray images, achieving more accurate and reliable flow predictions. Moreover, breakup processes are quantified by breakup length and sphericity in accordance with velocity estimations, allowing a more complete characterization of the flow. This study establishes a robust methodology for analyzing spray morphology and primary breakup in compact combustors, contributing valuable means of understanding and optimizing fuel spray behavior in advanced combustion systems.]]></description>
      <pubDate>Mon, 13 Apr 2026 16:48:09 GMT</pubDate>
      <guid>https://trid.trb.org/View/2688756</guid>
    </item>
    <item>
      <title>Assessing the Effect of Composition on Dielectric Constant of Sustainable Aviation Fuel</title>
      <link>https://trid.trb.org/View/2508971</link>
      <description><![CDATA[One of the challenges in developing 100% sustainable aviation fuels (SAFs) is the effect of synthetic blend components on the dielectric constant. Modern aircraft often employ capacitance-based gauging systems that rely on the dielectric constant of the fuel onboard to determine fuel quantity. Aircraft manufacturers have expressed concern over inaccuracies in fuel gauging attributable to variances in the dielectric constant between conventional jet fuels and 100% paraffinic sustainable aviation fuel. In this study, dielectric constant and density data were gathered from 172 conventional jet fuel samples to establish a baseline “experience range.” Subsequently, thirty-five individual hydrocarbon molecules from the jet fuel range and nine fuels were acquired, characterized, and reported herein according to the Clausius-Mossotti relationship. The findings indicate that different hydrocarbon group types exert varying effects on the Clausius-Mossotti relationship. To align with the established experience range for both the dielectric constant and the Clausius-Mossotti relationship, it appears that 100% drop-in SAF will need to incorporate some aromatic compounds. Finally, the authors explored two blending rules for the dielectric constant of jet fuel range hydrocarbons and achieved excellent coefficients of determination (R² values of 0.9942 and 0.9983, respectively).]]></description>
      <pubDate>Tue, 25 Feb 2025 13:51:27 GMT</pubDate>
      <guid>https://trid.trb.org/View/2508971</guid>
    </item>
    <item>
      <title>The Effect of Theoretical SAF Composition on Calculated Engine and Aircraft Efficiency</title>
      <link>https://trid.trb.org/View/2427750</link>
      <description><![CDATA[Whether the feedstock for sustainable aviation fuel (SAF) originates from agriculture or from waste streams, life cycle CO₂ emissions per unit enthalpy are lower for SAF than they are for petroleum distillates primarily because of differences on the front end such as fostered growth of crops or decreased demand for resources or acreage to manage wastes. This work, however, is concerned with what happens on the consumption side. Sustainable aviation fuel is required by ASTM D4054 / D7566 to meet a higher thermal stability standard than petroleum distillate fuels and this characteristic can be leveraged to improve energy efficiency in new engine or aircraft designs where a commitment has been made to burning fuel that meets a specification beyond that of conventional JetA. Beyond thermal stability, non-drop-in SAF (Jet-X) developers have the opportunity to further increase the value of their product by infusing higher-than-conventional-JetA energy density (enthalpy per unit volume, ED) into their SAF. Finally, fuel specific energy (enthalpy per unit mass, LHV) has a direct impact on aircraft efficiency which the authors have determined to be 0.43% per MJ/kg increase in LHV depending on the mission and aircraft model, and this is applicable to both drop-in and non-drop-in applications. While higher energy density fuels may be leveraged in a new aircraft design to decrease drag and weight, aircraft development potential with reduced tank volumes is typically constrained by other factors such as wing packaging, passenger volume requirements and overall center of gravity and flight control law restrictions.]]></description>
      <pubDate>Mon, 23 Sep 2024 09:05:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/2427750</guid>
    </item>
    <item>
      <title>Maximizing Sustainable Aviation Fuel Usage Through Optimization of Distillation Cut Points and Blending</title>
      <link>https://trid.trb.org/View/2301139</link>
      <description><![CDATA[Sustainable aviation fuel (SAF) pathways do not generally yield selective synthetic blend components in the aviation turbine fuel distillation range. Here the authors discuss a methodology for maximizing the sustainable aviation fuel yield from a pathway and the respective blend ratio with a petroleum-derived fuel by varying distillation cut points. These cut points are typically unique for each combination of feedstock and conversion technology and are essential independent variables for fuel finishing. The resultant cut point variations create a Pareto front, illuminating a competition between yield and blend ratio limits, i.e., the boundary where key operability properties are on the specification limit. Computational and experimental examples are given herein. In the computational case, eight bulk properties are calculated for a surrogate composition to simultaneously predict the competition between distillation yield and blend limit, with 10 points along the Pareto front experimentally verified. In the experimental optimization example, this methodology has been applied to an actual product stream currently under development. Relative to a third-party distillation cut recommendation, the method here yielded 37 %v more renewable carbon into the SAF fraction, while also affording a greater margin to property specification limits. This article shares the optimization process which can impact SAF qualification, the relative corresponding diesel and gasoline fractions, and business strategy.]]></description>
      <pubDate>Wed, 06 Dec 2023 17:02:36 GMT</pubDate>
      <guid>https://trid.trb.org/View/2301139</guid>
    </item>
    <item>
      <title>Towards Fuel Composition and Properties From Two-Dimensional Gas Chromatography With Flame Ionization and Vacuum Ultraviolet Spectroscopy</title>
      <link>https://trid.trb.org/View/2068014</link>
      <description><![CDATA[Already low volume (<1mL) test methods facilitate the development of sustainable aviation fuel platforms and higher fidelity computational methods. Here a novel technique with two-dimensional gas chromatography (GCxGC) and Vacuum Ultraviolet (VUV) identification is used to characterize fuel composition and determine properties compared to previous work. Ten properties are predicted, including the temperature dependence of density, viscosity, thermal conductivity, and heat capacity. Property predictions incorporate uncertainty quantification (UQ) from analyte quantification (UQ1), root property uncertainty (UQ2), and the uncertainty associated with isomeric variance (UQ3), when an analyte is not identified via VUV. Comparisons to a previous method illustrate the ability of VUV identification to increase the fidelity of property predictions and decrease uncertainties. This method is applied to a surrogate intended to mimic the first-order properties and composition of a representative Jet A/A-1. In addition to nominal and temperature-dependent properties, the derived cetane number (DCN) of the surrogate is calculated for the distillation fraction evolved. The DCN there is shown to vary across the fraction of fuel distilled. Collectively, this method documents a process to prescreen novel sustainable aviation fuel candidates, facilitate the development of chemical process models, and automate property determinations for computational fluid dynamics.]]></description>
      <pubDate>Mon, 28 Nov 2022 09:16:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2068014</guid>
    </item>
    <item>
      <title>Synthetic Aromatic Kerosene Property Prediction Improvements With Isomer Specific Characterization via GCxGC and Vacuum Ultraviolet Spectroscopy</title>
      <link>https://trid.trb.org/View/2068013</link>
      <description><![CDATA[This research explores an advanced method of fuel composition determination and builds upon typical hydrocarbon group type analyses performed with two-dimensional gas chromatography (GCxGC). In this study, structural information of individual species within Virent’s Synthetic Aromatic Kerosene (SAK) is identified by vacuum ultraviolet (VUV) spectroscopy. By mass, 71.3% of the components elute within six peaks of the chromatogram, from which 12 unique species are identified through a novel deconvolution method. Overall, the identification of 93.6%m across 26 structural isomers is made by the methods described in this work. With 93.6%m ascribed to specific isomers, the precision of fuel property predictions improves dramatically. For example, the absolute error of the viscosity prediction is reduced by 90% because of this advancement in diagnostic capability, and its 95-percentile confidence interval (precision only) is reduced by 93%. Additionally, the properties of SAK, blended with hydro processed esters fatty acids (HEFA), are demonstrated to have blended properties consistent with conventional jet fuel.]]></description>
      <pubDate>Mon, 28 Nov 2022 09:16:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/2068013</guid>
    </item>
    <item>
      <title>Pulp Mill Integration With Alcohol-to-Jet Conversion Technology</title>
      <link>https://trid.trb.org/View/1868895</link>
      <description><![CDATA[This study examines the integration of commercial liquid fuels production from biomass using the alcohol-to-jet pathway into a conventional kraft pulp mill operation. Mill assets including feed handling and supply chain infrastructure, power and recovery systems, and potential equipment retrofitting opportunities are utilized by a fuel production unit through lignocellulosic ethanol fermentation and alcohol-to-jet processing. Potential economic benefits of integrating the energy recovery system (recovery boiler) of the pulp mill with the biomass pretreatment systems are evaluated through energy and mass balances of the integrated facility. Process variations explored within this model include the use of hemicellulose pre-extraction or black liquor fractionation, modifications to digester operations and the scale of a mill retrofitting project. The production of liquid fuels is found to provide a relative reduction in energy use compared to pulp production. With the low energy costs provided by this design, maintaining a high yield throughout the conversion process and the reduction of capital costs offer the best opportunities for further improving economics. Although the economic viability of a realistic biorefinery is not directly evaluated in this study, the aim is to identify technical barriers and opportunities for development of integrated strategies for implementing proven biofuels production technologies.]]></description>
      <pubDate>Wed, 22 Sep 2021 12:03:08 GMT</pubDate>
      <guid>https://trid.trb.org/View/1868895</guid>
    </item>
    <item>
      <title>Sustainable Alternative Fuel Effects on Energy Consumption of Jet Engines</title>
      <link>https://trid.trb.org/View/1868894</link>
      <description><![CDATA[High thermal stability enables engine manufacturers to increase the reliance on fuel as a heat sink while reducing the reliance on air, which wastes the energy used to compress it or increases aircraft drag. While the direct impact of waste heat recovery can translate into an energy savings of 0.2% if the maximum fuel temperature limit is increased to 160 °C (from 127 °C), there is a larger impact from a variety of options to improve the thermal efficiency of the engine. In this work, it is predicted that a combined savings of 0.5% or more is possible, 60% of which stems from leveraging the high thermal stability that synthetic fuels can afford. The engine performance and fuel system models that were developed to make these predictions, together with previously developed models to predict fuel properties from composition, have also been used in a series of Monte Carlo simulations to gage the impact of fuel composition variation on engine efficiency. A range of increased efficiency of 0.17% or 0.25% is predicted at high and low power, respectively. This works establishes a methodology to incorporate jet engine efficiency as an objective function in an algorithm designed to optimize sustainable alternative (jet) fuel composition.]]></description>
      <pubDate>Wed, 22 Sep 2021 12:03:05 GMT</pubDate>
      <guid>https://trid.trb.org/View/1868894</guid>
    </item>
    <item>
      <title>A Shock Tube Study of Jet Fuel Pyrolysis and Ignition at Elevated Pressures and Temperatures</title>
      <link>https://trid.trb.org/View/1871723</link>
      <description><![CDATA[The development of compact HyChem hybrid models for jet fuels requires datasets of pyrolysis product yields to constrain the model and of kinetic targets to evaluate the model. To this end, the authors have measured selected species time-histories during fuel pyrolysis using laser absorption, and ignition delay times using multiple methods behind reflected shock waves in a heated shock tube. Measurements were performed for three different jet fuels diluted in air or argon over a temperature range of 1000–1400 K, a pressure range of 12–40 atm, and equivalence ratios of 0.5–1. Fuel loading was measured using an IR He-Ne laser at 3391 nm; ethylene with a CO₂ gas laser at wavelengths of 10532 nm and 10674 nm; and methane with a tunable diode laser at wavelengths of 3175 nm and 3177 nm. Ignition delay times were measured in three ways: by monitoring fuel removal with laser absorption, by sidewall pressure, and by OH∗ emission. Particular care was taken in mixture preparation and efficient transfer of the gaseous fuel mixture to the shock tube. The current HyChem model by Wang et al. shows good agreement with these data.]]></description>
      <pubDate>Mon, 30 Aug 2021 14:46:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1871723</guid>
    </item>
    <item>
      <title>On Estimating Physical and Chemical Properties of Hydrocarbon Fuels Using Mid-infrared FTIR Spectra and Regularized Linear Models</title>
      <link>https://trid.trb.org/View/1871720</link>
      <description><![CDATA[The concept of a compact, economical Fourier-transform infrared (FTIR)-based analyzer for estimating the properties of hydrocarbon fuels with small amounts of fuel is proposed. The high correlations between mid-infrared (IR) FTIR absorption spectra of fuel vapor in the range 3300–3550 nm and 15 physical and chemical properties, such as density, initial boiling point, surface tension, kinematic viscosity, number of carbon and hydrogen per average molecule, and derived cetane number, for 64 hydrocarbon fuels are demonstrated. Lasso-regularized linear models based on linear combination of absorption cross sections at selected wavelengths are built for each of these physical and chemical properties, yielding accurate estimations.]]></description>
      <pubDate>Mon, 30 Aug 2021 14:46:30 GMT</pubDate>
      <guid>https://trid.trb.org/View/1871720</guid>
    </item>
    <item>
      <title>Sustainable Aviation Fuel Prescreening Tools and Procedures</title>
      <link>https://trid.trb.org/View/1870416</link>
      <description><![CDATA[This paper outlines the benefits and procedures for prescreening Sustainable Aviation Fuel (SAF) candidates before entering the official ASTM D4054 evaluation process. Specific properties are identified, that if not met, may result in extensive and costly efforts to correct if not recognized until later in the fuel development process. Hence, an approach with specific techniques that use low fuel volumes is suggested that enable (1) early estimates of critical properties and subsequently (2) direct measurement of these properties to guide fuel processing development prior to formally entering the ASTM evaluation process. The process is demonstrated with two exemplary candidate fuels.]]></description>
      <pubDate>Wed, 25 Aug 2021 17:18:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/1870416</guid>
    </item>
    <item>
      <title>High-performance jet fuel optimization and uncertainty analysis</title>
      <link>https://trid.trb.org/View/1857782</link>
      <description><![CDATA[High-performance jet fuel represents a subset of sustainable aviation fuel that improves the value and performance of the fuel while reducing greenhouse gas emissions and remaining within ‘drop-in’ operability and safety limits. Here, performance gains via increased specific energy [MJ/kg] and energy density [MJ/L] achievable with high-performance jet fuel have been bound by optimizing blends of molecules considering 10 operability and safety properties. Aleatoric and epistemic uncertainties associated with the optimization have been quantified using Latin hypercube sampling, with the associated variance in performance, composition, and operability properties reported. Two optimization scenarios were considered-one with and one without the 8% minimum aromatic requirement- to determine the effect on fuel performance and composition while exploring the possibility of replacing aromatics with cycloalkanes in jet fuel. The results of this study are average specific energy/energy density increases of 1.61/2.36% and 1.84/2.46% relative to Jet A with and without the aromatic constraint respectively, indicating that aromatics are not desirable for fuel performance. Uncertainty for performance properties was low with 1s and 2s values at ±0.2% and ±0.4% of the average Pareto front values for both scenarios, which suggests that this study is a good indicator of the performance benefits that can be conferred via high-performance jet fuel. Compositions were biased heavily toward cycloalkanes at 70% and 81% respectively, with low-temperature viscosity and density serving as the limiting operability constraints. This study concludes that cycloalkanes can replace aromatics in jet fuel considering operability limits while increasing fuel performance and reducing soot emissions.]]></description>
      <pubDate>Fri, 23 Jul 2021 15:23:39 GMT</pubDate>
      <guid>https://trid.trb.org/View/1857782</guid>
    </item>
    <item>
      <title>Renewable bio-jet fuel production for aviation: A review</title>
      <link>https://trid.trb.org/View/1862589</link>
      <description><![CDATA[Due to excessive greenhouse gas emissions and high dependence on traditional petroleum jet fuel, the sustainable development of the aviation industry has drawn increasing attention worldwide. One of the most promising strategies is to develop and industrialize alternative aviation fuels produced from renewable resources, e.g. biomass. Renewable bio-jet fuel has the potential to reduce carbon dioxide (CO₂) emissions over their life cycle, which make bio-jet fuels an attractive substitution for aviation fuels. This paper provided an overview on the conversion technologies, economic assessment, environmental influence and development status of bio-jet fuels. The results suggested that hydrogenated esters and fatty acids, and Fischer-Tropsch synthesis can be the most promising technologies for bio-jet fuels production in near term. Future works, such as searching for more suitable feedstock, improving competitiveness for alternative jet fuels, meeting emission reduction targets in large-scale production and making measures for the indirect impact are needed for further investigation. The large-scale deployment of bio-jet fuels could achieve significant potentials of both bio-jet fuels production and CO₂ emissions reduction based on future available biomass feedstock.]]></description>
      <pubDate>Wed, 30 Jun 2021 12:01:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/1862589</guid>
    </item>
    <item>
      <title>A Machine Learning Framework for Drop-In Volume Swell Characteristics of Sustainable Aviation Fuel</title>
      <link>https://trid.trb.org/View/1851830</link>
      <description><![CDATA[A machine learning framework has been developed to predict volume swell for 10 non-metallic materials sub-merged in neat compounds. The non-metallic materials included nitrile rubber, extracted nitrile rubber, fluorosilicone, low temp fluorocarbon, lightweight polysulfide, polythioether, epoxy (0.2 mm), epoxy (0.04 mm),nylon, and Kapton. Volume swell, a material compatibility concern, serves as a significant impediment for the minimization of the greenhouse gas emissions of aviation. Sustainable aviation fuels, the only near and mid-term solution to mitigating greenhouse gas emissions, are limited to low blend limits with conventional fuel due to material compatibility issues (i.e. O-ring swell). A neural network was trained to predict volume swell for non-metallic materials submerged in neat compounds. Subsequent blend optimization incorporated nitrile rubber volume swell predictions for iso- and cycloalkanes to create a high-performance jet fuel within ‘drop-in’ limits. The results of this study are volume swell predictions for 3 of the 10 materials -nitrile rubber, extracted nitrile rubber, and polythioether- with holdout errors of 12.4% or better relative to mean volume swell values. Optimization considering nitrile rubber volume swell achieved median specific energy [MJ/kg] and energy density [MJ/L] increases of 1.9% and 5.1% relative to conventional jet fuel and an average volume swell of 6.2%v/v which is within the range of conventional fuels. Optimized solutions were heavily biased toward mono-cycloalkanes, indicating that they are a suitable replacement for aromatics. This study concludes that cycloalkanes can replace aromatics in jet fuel considering volume swell and other operability requirements while significantly reducing soot and particulate matter emissions.]]></description>
      <pubDate>Tue, 25 May 2021 16:20:02 GMT</pubDate>
      <guid>https://trid.trb.org/View/1851830</guid>
    </item>
    <item>
      <title>Trajectory Optimization of Electric Vehicles for Eco-Driving Applications</title>
      <link>https://trid.trb.org/View/1681583</link>
      <description><![CDATA[Due to environmental concerns and scarcity on non-renewable fossil fuels researchers are currently looking for new, more fuel efficient solutions in the transportation sector. With its ability to regenerate kinetic energy while braking the electric vehicle is an attractive solution. In addition the electrification gives flexibility for the source of energy chosen to generate the electricity. One way to improve energy efficiency of road vehicles is to adapt their utilization to the system operation. The concept of eco-driving refers to a driver behavior that minimizes energy consumption. While the efficient operation of a conventional vehicle might be intuitive, the general driver does not know how to optimally operate an electric vehicle. With this work we are trying to identify potential gains in energy consumption as well as to detect factors that are important for eco-driving. The paper presents a system model of a small electric vehicle. In order to compute the energetically optimal velocity trajectory the dynamic programming optimization method is applied. For comparison, normal driving is defined using stored real-life drive cycles. Given the drive cycle optimization constraints are defined in time, distance and speed. The calculated optimal velocity trajectories are analyzed in order to identify important eco-driving factors. To verify the potential eco-driving gains the trajectories were tested in an experimental setting on a chassis test bench.]]></description>
      <pubDate>Tue, 28 Jan 2020 16:14:42 GMT</pubDate>
      <guid>https://trid.trb.org/View/1681583</guid>
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