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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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    <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>Data-driven battery aging diagnostics and lifetime extension</title>
      <link>https://trid.trb.org/View/2534273</link>
      <description><![CDATA[Transportation electrification is critical to mitigating climate change, with lithium-ion (Li-ion) batteries playing a pivotal role in the shift to low-carbon energy sources. Given that batteries can account for up to 50% of an electric vehicle's cost, optimizing their lifespan and performance is critical for cost-effective operation. Batteries though, degrade in ways that are inhomogeneous, nonlinear, and dependent on multiple factors. This makes accurate aging diagnostics and prognostics essential for ensuring their safe, efficient use. Diverse operating conditions, complex aging mechanisms, unpredictable usage profiles, and cell-to-cell variations pose significant challenges. At the same time, battery performance, including energy and power, is influenced not only by health state but also by conditions such as temperature, State of Charge (SoC), and applied current. This thesis presents a series of machine learning (ML) frameworks developed using field data from vehicles and laboratory cycling data. One proposed framework is a battery capacity estimation algorithm that integrates multiple ML models with a Kalman filter, accommodating the diverse usage profiles of electric vehicles (EVs) in real-world scenarios. To reduce warranty costs, a histogram-based usage-related ML framework is developed, combining offline global models with online cell-specific models to track and predict future aging. Additionally, a remaining useful life (RUL) prediction model improves accuracy by combining usage and time-series data is developed as well. Beyond aging diagnostics, the thesis proposes a method to extract relationships between battery performance indicators (PIs) and various influencing factors like temperature, SoC, and aging, using a neural network-based framework. Lastly, it introduces an online method to estimate battery plating potential, enabling faster charging while minimizing lithium plating risks to extend the lifetime of the battery. Collectively, these contributions provide practical tools for diagnostics, prognostics, and control, advancing safer, more efficient, and cost-effective use of Li-ion batteries in EVs.]]></description>
      <pubDate>Fri, 04 Apr 2025 15:16:00 GMT</pubDate>
      <guid>https://trid.trb.org/View/2534273</guid>
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    <item>
      <title>Right-Sizing Concept for Improving Thermal Efficiency of Diesel Engine at Partial Load (First Report)</title>
      <link>https://trid.trb.org/View/2384481</link>
      <description><![CDATA[The purpose of this study is improving fuel economy at part load operation for light commercial vehicles. 0-D engine simulation results show that increasing displacement and removing turbocharger solve multiple trade-offs between component technologies that are barriers to improving thermal efficiency. A prototype engine was produced to verify the effectiveness of this right-sizing concept. As a result of prototype demonstration, the concept engine can meet Japan’s post-Post New Long-Term emissions regulations while improving thermal efficiency.]]></description>
      <pubDate>Mon, 24 Jun 2024 09:26:55 GMT</pubDate>
      <guid>https://trid.trb.org/View/2384481</guid>
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    <item>
      <title>Right-Sizing Concept for Improving Thermal Efficiency of Diesel Engine at Partial Load (Second Report)</title>
      <link>https://trid.trb.org/View/2384472</link>
      <description><![CDATA[In the first report, right-sizing concept was proposed. Essence of the proposed concept is a naturally aspirated engine eliminating EGR. Also, this concept obtains low density in-cylinder condition and low Pₘₐₓ operation. In this report, the combustion parameters were optimized under low density condition in-cylinder using 3-D simulation. Furthermore, friction reduction technologies were developed based on advantage of low Pₘₐₓ operation. As the results, the prototype engine with combining all technologies demonstrated that the maximum thermal efficiency can be obtained as intended at partial load.]]></description>
      <pubDate>Mon, 24 Jun 2024 09:26:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2384472</guid>
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    <item>
      <title>Application of a Numerical Model on Displacement Correction to the Evaluation of Ship Performance in Calm Seas for a Bulk Carrier Using Ship Monitoring Data</title>
      <link>https://trid.trb.org/View/1974217</link>
      <description><![CDATA[For the accurate evaluation of the ship performance in actual seas, the relationship among the ship speed, the engine revolution and the engine power in calm seas is important. One method to obtain the relationship is to use the onboard monitoring data. The approximate curve is obtained by the least-square method. In this method, it is important that the number of the data is enough in the appropriate range of the engine revolution or the ship speed. However in the case of a bulk carrier, the range of the engine revolution and the ship speed is narrow in one voyage. In this paper, a new numerical model is applied to a bulk carrier in service. The data is filtered by the wind speed, the significant wave height, the difference between the ship speed through the water and over ground and the rudder angle. Moreover the corrections for the external force and the combination of the data of each voyage are carried out. The approximate curve is obtained in a numerical expression using parameters “aₙ”, “bₙ”, “cₙ” and “dₙᵥ”, and the displacement correction model is obtained. The difference between the simulation and the monitoring data of the ship speed and the fuel oil consumption is within 2%.]]></description>
      <pubDate>Mon, 20 May 2024 14:02:20 GMT</pubDate>
      <guid>https://trid.trb.org/View/1974217</guid>
    </item>
    <item>
      <title>Enabling off-highway diesel engine downsizing and performance improvement using electrically assisted turbocharging</title>
      <link>https://trid.trb.org/View/2247646</link>
      <description><![CDATA[Internal combustion engine (ICE) downsizing through various turbocharging configurations is generally known by the powertrain design community as an effective means to reduce frictional losses, increase waste heat recovery, and improve fuel efficiency while increasing engine power density. However, often is the case that turbocharging strategies, including variable geometry turbochargers, and regulated two-stage turbochargers, incur the performance tradeoff between transient response and fuel economy (pumping losses) at high engine speeds. For off-highway vehicles having particularly transient and high-powered duty cycles, efforts to improve this tradeoff and increase operational flexibility have turned to evaluating various electrified air system architectures. In this study, a 4.5 L diesel-ICE configured with an electrically driven compressor (eBooster®) is placed in series with a conventional turbocharger and integrated into a 48 V mild-hybrid powertrain architecture. The objective of this powertrain configuration is to enable engine downsizing by 34%, replacing the current 6.8 L ICE platform with the hybridized 4.5 L ICE concept. The commercial 1-D simulation software GT-SUITE is used for powertrain system development and system optimization. Development and validation of the GT-SUITE model and air system controls is concurrently supported through experimental data collection. The simulation model development includes using machine learning methods for optimizing exhaust gas dilution, injection timing, and eBooster® power to improve steady-state and transient brake-specific fuel consumption while minimizing criteria pollutant emissions. It was found that total specific fluid consumption over the standardized non-road transient engine duty cycle could be reduced by 18% over the current 6.8 L engine by using an optimized eBoosted 4.5 L engine. The hybridized 4.5 L engine concept concurrently showed sufficient transient response capability and nearly an order of magnitude reduction in duty cycle total soot production.]]></description>
      <pubDate>Mon, 16 Oct 2023 17:26:23 GMT</pubDate>
      <guid>https://trid.trb.org/View/2247646</guid>
    </item>
    <item>
      <title>Dynamic cylinder deactivation: Thermodynamic mapping for the case of stoichiometric SI ICE</title>
      <link>https://trid.trb.org/View/2140217</link>
      <description><![CDATA[Conventional cylinder deactivation has been improving internal combustion efficiency for decades. It provides benefits for any internal combustion engine, particularly engines with high number of cylinders. The level of engine displacement reduction depends on the number of cylinders that may be deactivated during operation. This limits the potential benefit. Theoretically, maximum benefit of cylinder deactivation would require assignment of specific displacement reduction to each engine operating point. Dynamic cylinder deactivation is a new approach, which does not continuously deactivate cylinders, but deactivates selected engine cycles. This allows to dynamically reduce engine displacement and to assign optimum displacement reduction to each operating point. The paper deals with the one-dimensional thermodynamic simulation of the dynamic cylinder deactivation applied to a small displacement four-cylinder gasoline engine, points out crucial attributes of this new approach and compares it with baseline engine layouts and with the conventional cylinder deactivation as well. The research concludes that the dynamic cylinder deactivation improves the fuel consumption for engines loads BMEP < 5bar. Deactivation strategy with the lowest trapped mass value in the deactivated cycle shows the most benefit.]]></description>
      <pubDate>Tue, 23 May 2023 10:12:38 GMT</pubDate>
      <guid>https://trid.trb.org/View/2140217</guid>
    </item>
    <item>
      <title>Development of 1.5L Diesel Engine for Stage V with common rail system</title>
      <link>https://trid.trb.org/View/2104372</link>
      <description><![CDATA[Recently, EU StageV emissions regulations have been enforced in the European market since 2019, increasing environmental requirements for diesel engines. EU StageV has been tightened compared to EPA Tier4 regulation, which demand PM (Particulate Matter) reduction and added new PN (Particle Number) regulations. Until the previous regulation EU Stage IIIA, the power category of 19kW or more and less than 37 kW had adopted mechanical IDI (Indirect-Injection). This mechanical engine is characterized by compactness and lightweight because of simple structure. Therefore, this engine is appreciated by customer with easy installation. On the other hand, to achieve EU StageV, it is necessary to adopt the electronic direct injection common rail system with more precise fuel injection and advanced exhaust gas aftertreatment device. The newly developed V1505-CR-T engine is not only small displacement of 1.5L, but also four-cylinders, and it is low vibration in addition compactness and lightweight. However, the bore of this engine is smaller than other similar displacements, because it is the unique four-cylinders. It was modified to DI (Direct-Injection) for the first time at this displacement, and common rail system was adopted. By applying Center-Direct-Injection-System, in which the injectors are arranged vertically at the center of combustion chamber, it was possible to inject fuel uniformly. Therefore, air and fuel are easily mixed even in small bore and small combustion chamber. Furthermore, Intake and Exhaust system were changed from two valves to four valves to intake more air. Regarding the concern that these modifications may increase engine dimensions, the exhaust emissions reduction device was specially designed, and the authors realized compactness and lightweight by new built-in arrangements such as the EGR (Exhaust Gas Recirculation) gas route into cylinder-head and the oil separator for the breather into cylinder head cover. In this article, the authors introduce techniques to comply with EU StageV on small bore engine and small combustion chamber.]]></description>
      <pubDate>Thu, 23 Mar 2023 10:20:48 GMT</pubDate>
      <guid>https://trid.trb.org/View/2104372</guid>
    </item>
    <item>
      <title>The Influence of the Notch Shape and Number on Proportional Directional Control Valve Metering Characteristics</title>
      <link>https://trid.trb.org/View/1802087</link>
      <description><![CDATA[The paper investigates, by means of a 3D, steady-state, incompressible and isothermal CFD analysis, the influence of the notch shape and number on proportional directional control valves metering edge characteristics. The numerical activity is firstly performed for a sharp metering edge, considered as reference case. Then, different configurations of notched metering edges are considered, coming from the adoption of two notch geometrical shapes largely used in proportional directional control valves actual design, and from a symmetrical displacement of two, three and four notches on the spool periphery. For all the cases considered, the qualitative analysis of the internal flow field is performed in order to highlight the fluid efflux main characteristics. After, a quantitative analysis of the metering characteristics is introduced, with the aim of determining the influence of the metering configuration, of the spool position and of the operating conditions on the efflux characteristics (the discharge coefficient and the jet angle).]]></description>
      <pubDate>Mon, 29 Aug 2022 11:32:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1802087</guid>
    </item>
    <item>
      <title>Load Case Characterization and Modal Coordinate Estimates from Damper Displacements</title>
      <link>https://trid.trb.org/View/1802084</link>
      <description><![CDATA[This paper evaluates estimations of modal coordinates from chassis damper displacements on heavy vehicles. The objective is to study to what extent relative displacements are sufficient as control input for semi active damping systems. The possibility to combine passive damping requirements at different driving conditions is furthermore investigated by studying damper displacements in the phase plane. For both objectives, vehicle simulations with a 3D - tractor semi trailer model are utilized. Results show that modal coordinate estimates based solely on relative damper displacements, during impact for transient load cases show significant discrepancies to actual motion. For subsequent free oscillations, modal coordinates may however be estimated this way. Phase plane plots are finally shown to be useful tools to illustrate conflicting demands on passive damping characteristic and to rate expected benefits from different damper techniques.]]></description>
      <pubDate>Mon, 29 Aug 2022 11:32:21 GMT</pubDate>
      <guid>https://trid.trb.org/View/1802084</guid>
    </item>
    <item>
      <title>An Improvement of a Small Displacement Engine's Efficiency with a Super Charging System</title>
      <link>https://trid.trb.org/View/1825275</link>
      <description><![CDATA[Many environmental problems, such as global warming, drain of fuel and so on, are apprehended in all over the world today, and down-sizing is one of the wise ways to deal with these problems. It is significant that a decrease of the engine power must not be produced by using a small displacement engine, so more efficient engine system should be designed to increase the torque with a little fuel. This study achieves an improvement of efficiency for mounting the super charging system on the small displacement engine. As a result, comparing a super charged engine and a naturally aspirated one to drive the same course and laps, fuel consumptions are 2547 [cc] and 3880 [cc], respectively, and an improvement of fuel consumption is 52%. Designing points to mount super charging system is introduced below. 1-It can be forecasted that intake air blow-by gas at the combustion chamber is increased in low engine speed because engine for motor cycle is used. Therefore, the valve timing (cam profile) is changed. 2-Stress analysis and fluid flow analysis were done for the new intake chamber made by powder laminated casting. The sectional area of the new intake chamber is set to become gradually smaller, in order to increase the flow rate. 3-Inter cooler is adapted, because intake air compressed with super charger becomes hot and it causes a decrease of charging efficiency and an increase of the knocking of an engine. 4-The fuel injection map and the ignition timing map are optimized for changes above. These changes above made it possible to make higher torques for a wider range of engine speeds, and this leads to low fuel consumption. It is because that coming down torque peak and average engine speed reduce engine friction. In this way, the value of fuel consumption with super charger can be lower than the one with naturally aspirated.]]></description>
      <pubDate>Fri, 17 Jun 2022 09:20:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1825275</guid>
    </item>
    <item>
      <title>Characterization of Ethanol Blends Combustion Processes and Soot Formation in a GDI Optical Engine</title>
      <link>https://trid.trb.org/View/1828442</link>
      <description><![CDATA[This paper deals with the evaluation of the effect of fuel properties on soot formation in a GDI (gasoline direct injection) engine. Experimental investigation was carried out in an optical 4-stroke small single cylinder engine for two-wheel vehicles. The engine displacement was 250 cc. It was equipped with an elongated piston with a wide sapphire window in the head and a quartz cylinder liner. The engine was fuelled with pure gasoline and ethanol, and ethanol/gasoline blends at 20% v/v, 50% v/v and 85% v/v. Optical techniques based on 2D-digital imaging were used to follow the combustion process and soot formation. Spectroscopic measurements were carried out in order to assess the soot evolution. Radical species such as OH and CH, related to fuel quality and to soot formation/oxidation process, were detected. Measurements were carried out at various engine speeds and loads in order to allow optical measurements and to test the engine in real conditions. Regulated gas emissions and opacity were measured at the exhaust by conventional equipment. Moreover, particle emissions were characterized also in terms of number concentration and size distribution using a differential mobility sizer.]]></description>
      <pubDate>Tue, 24 May 2022 10:09:45 GMT</pubDate>
      <guid>https://trid.trb.org/View/1828442</guid>
    </item>
    <item>
      <title>Development of a New 2.0-Liter Fuel-Efficient Diesel Engine</title>
      <link>https://trid.trb.org/View/1827863</link>
      <description><![CDATA[Toyota Motor Corporation aims to develop vehicles that are both fun to drive and fuel efficient, using highly reliable, low cost, and fundamental technology. This approach focuses on the accumulation of incremental improvements to combustion characteristics and friction, making the best use of the maximum potential of the displacement of a new 2.0-liter fuel-efficient diesel engine. This new engine has been launched in several markets around the world for the Avensis, the Auris, the RAV4, and the Verso since November of 2011. This paper presents an outline of this new engine and its technology.]]></description>
      <pubDate>Mon, 25 Apr 2022 17:01:17 GMT</pubDate>
      <guid>https://trid.trb.org/View/1827863</guid>
    </item>
    <item>
      <title>Vibration Reduction in a Variable Displacement Engine Using Pendulum Absorbers</title>
      <link>https://trid.trb.org/View/1797474</link>
      <description><![CDATA[This paper describes the design, implementation and testing of crankshaft-mounted pendulum absorbers used for reducing vibrations in a variable displacement engine. The engine can run in V8 and V4 modes, and without absorbers it experiences significant vibration levels, especially in V4 idle. The absorbers are tuned to address the dominant second order vibrations, and are slightly overtuned to account for nonlinear effects. The absorbers were designed to replace the large counterweights at the ends of the crankshaft, and thus serve for both balancing and vibration absorption. The engine was placed in a vehicle and tested for vibration levels at idle under various load conditions, and these results were compared with results obtained from a similar vehicle without absorbers. The tests demonstrate that these absorbers offer an effective means of vibration attenuation in variable displacement engines.]]></description>
      <pubDate>Wed, 23 Feb 2022 16:16:14 GMT</pubDate>
      <guid>https://trid.trb.org/View/1797474</guid>
    </item>
    <item>
      <title>Use of Vibratory Power Flows to Assess the Effectiveness of a Vibration Isolation Design</title>
      <link>https://trid.trb.org/View/1804657</link>
      <description><![CDATA[Power flows from a vibratory machine to its mounting structure are of primary concern in passive or active isolation system designs. The total power flow is increasingly believed to be a more reasonable measure of the effectiveness of a vibration isolation system as compared with the traditional measure in terms of the force or displacement transmissibility. In order to calculate the power flows, one needs to know the reaction forces and the vibrations at the isolator locations on the mounting structure. In this paper, the process of determining the power flows through the vibration isolators is discussed for some commonly-used mounting structures which include platforms (reinforced plates), cylindrical shells and other complicated structures. The power flows through the rotational displacements or the bending stiffnesses of the isolators have been taken into account, which tends to become important at high frequencies. Numerical examples are given to show the modal and power flow characteristics of a composite vibration isolation system.]]></description>
      <pubDate>Wed, 23 Feb 2022 16:16:13 GMT</pubDate>
      <guid>https://trid.trb.org/View/1804657</guid>
    </item>
    <item>
      <title>Estimation of Powertrain Inertia Properties via an In-situ Method</title>
      <link>https://trid.trb.org/View/1812159</link>
      <description><![CDATA[An experimental method has been developed which allows the rigid body inertia properties of an automotive type powertrain to be estimated in-situ without removing the powertrain from the vehicle. The method requires that the complex stiffness properties of the powertrain mounts be estimated therefore allowing through the measurement of the relative displacements across the mounts for the estimation of the forces generated at the powertrain mount locations. Rigid body motion measurements are made through the use of accelerometers simultaneous to exciting the powertrain with multiple shakers. Results of the method are compared to those acquired through an inertia pendulum and the FRF based method implemented in LMS Cada-X software. Effects on the results due to shaker location, response location, mount variation, and removal of powertrain peripherals are also investigated. The method is validated through both an actual vehicle's powertrain estimation as well as through the testing of a rigid mass with known inertia properties which simulate those of a front wheel drive sedan's powertrain.]]></description>
      <pubDate>Wed, 23 Feb 2022 16:16:12 GMT</pubDate>
      <guid>https://trid.trb.org/View/1812159</guid>
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