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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>
      <url>https://trid.trb.org/Images/PageHeader-wTitle.jpg</url>
      <link>https://trid.trb.org/</link>
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    <item>
      <title>Numerical simulation and optimization of injector and nozzle pattern of an opposed-piston two-stroke diesel engine</title>
      <link>https://trid.trb.org/View/2706079</link>
      <description><![CDATA[Opposed-Piston Two-Stroke (OP2S) diesel engine shows high-power density, low heat transfer loss and good balance performance. However, side-mounted injectors must be used because of their special architecture, which makes it necessary to redesign the injector. In this paper, the effects of injector nozzles arrangement, including the number of injectors, the number of nozzles and their installation position, on the mixing and combustion performance were studied by using CFD simulation. Results show that the distribution of the equivalence ratio was significantly influenced by the effects of in-cylinder swirl and injection pattern. This swirl-induced interaction among gaseous fuel, leading to their aggregation, subsequently affects the combustion rate. An adequate space among the injector nozzles is essential for improving air utilization and combustion process. Altering the injector mounting angle allowed for the exploitation of in-cylinder micro-tumble, which could enhance droplet breakup and subsequently improved the mixing and combustion processes, and the Indicated Mean Effective Pressure (IMEP) could be increased by 6.42% compared to the prototype engine, yet with fewer injectors.]]></description>
      <pubDate>Thu, 13 Aug 2026 17:07:15 GMT</pubDate>
      <guid>https://trid.trb.org/View/2706079</guid>
    </item>
    <item>
      <title>Phenomenological combustion modeling with swirl effects of a two-stroke marine engine for digital twins</title>
      <link>https://trid.trb.org/View/2679085</link>
      <description><![CDATA[In a marine two-stroke engine, swirl flow dominates in the cylinder due to its uniflow scavenging process. The fuel spray and its flame are deflected by the swirl and result in different impingement characteristics on the cylinder wall, which may affect thermal stress/loss and engine’s lifetime of lubrication system. To study the influence of spray and swirl on the combustion of marine low-speed diesel engines, a phenomenological spray and combustion model is developed to predict the spray evolution under the swirl effect. The deflection velocity of the spray is calculated using the momentum conservation theory, and the combined velocity of the spray is determined by superimposing the deflection velocity with the initial velocity of the spray. During combustion, the burned fuel is consumed with a premixed stage and a diffusion stage, while the unburned fuel spray continues the deflection. The simulation results of the phenomenological model are validated by experimental results of a Constant Volume Combustion Chamber (CVCC) and a marine two-stroke engine. The wall impingement in different engine conditions predicted by the proposed model is verified by a CFD engine model. Therefore, the phenomenological spray and combustion model can predict the marine engine performance, while providing the impingement timing for thermal load estimation. In the future, this model could be applied in a digital twin system for engine control decisions with restrictions of spray impingement and thermal load, which may reduce the maintenance efforts.]]></description>
      <pubDate>Wed, 10 Jun 2026 13:40:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2679085</guid>
    </item>
    <item>
      <title>Application of electronic fuel injection in two-stroke piston engines for UAS</title>
      <link>https://trid.trb.org/View/2665823</link>
      <description><![CDATA[Low weight, a good power-to-weight ratio, and simple construction are the main features of two-stroke engines used in aviation. They are most commonly found in medium-sized drones powered by high-speed, multi-cylinder, low-displacement engines. However, this simplicity of construction comes at the cost of reduced efficiency, reliability, and even maximum power output. These disadvantages can be mitigated through the use of electronic engine control. As a result, drones could achieve higher speeds, carry heavier payloads, or the engines could be adapted for use in other experimental flying machines. For our research, we used a 1960s car engine that had been employed in various low-cost ultralight aircraft of the time, such as the Straton D7. This work describes both the modification of the engine for use in the aircraft and its subsequent adaptation for electronic control.]]></description>
      <pubDate>Mon, 23 Mar 2026 15:15:33 GMT</pubDate>
      <guid>https://trid.trb.org/View/2665823</guid>
    </item>
    <item>
      <title>Injection rate of cylinder lubrication oil in large two-stroke marine diesel engines using a common rail lubrication system</title>
      <link>https://trid.trb.org/View/2628235</link>
      <description><![CDATA[This article investigates a common rail cylinder lubrication system for large two-stroke marine diesel engines using electronically controlled injectors. The system is studied using the Bosch rate of injection measurement technique. The common rail injector has a buildup of mass flow of approximately 1 ms as the injector opens until the nozzle is choked from cavitation. Using a highly viscous fluid, the Bosch rate of injection method is able to predict the injected amount with an error of 5% or lower for nearly the entire tested delivery range of 2–21 mg. Lubrication of cylinder liners and piston rings is a crucial parameter in operating a two-stoke marine diesel engine efficiently. Both over and under lubrication is harmful for the engine, so the ability to accurately dose the cylinder oil is very important. A mass flow build up time of 1 ms promises high accuracy of dosage even down to 2.5 mg per injection. This paves the way for injecting the oil where and when it is needed, which in turn will improve engine performance and lower harmful emissions.]]></description>
      <pubDate>Tue, 03 Feb 2026 10:07:07 GMT</pubDate>
      <guid>https://trid.trb.org/View/2628235</guid>
    </item>
    <item>
      <title>Experimental study of airpath electrification in an opposed-piston two stroke (OP2S) engine architecture</title>
      <link>https://trid.trb.org/View/2612402</link>
      <description><![CDATA[The opposed-piston two stroke (OP2S) engine shows potential as an alternative engine architecture to the conventional four stroke engine due to its high-power density, thermal efficiency, and versatile airpath management system. Since the pistons of a two-stroke engine do not pump the air into and out of the cylinder like in a four-stroke engine, the selection of the air induction devices and airpath actuators becomes critical to optimize engine performance. Both the pumping losses and the in-cylinder combustion process can be affected by the scavenging process in a two-stroke engine. Therefore, this study compares two different airpath configurations for the same family of OP2S engines and investigates performance metrics like scavenging control, pumping work, net indicated and brake efficiencies, and engine-out emissions associated with each airpath. Data was collected on a 3.2 L, two-cylinder OP2S engine with an electrically assisted turbocharger (EAT) and a 4.9 L displacement, three-cylinder engine with a variable geometry turbocharger (VGT) and a supercharger. The experiments consisted of speed and load sweeps for both engines at the same operating conditions to compare scavenge control in both architectures. For the three-cylinder layout, the SE sweep range was much higher, and the intake pressure could be independently varied with air flowrate, thus providing more flexibility for scavenging control. The supercharger and the VGT usage was optimized based on its efficiency map and thus, this layout had lower pumping losses compared to the EAT. The two-cylinder engine had a higher overall SE as compared to the three-cylinder engine, but the intake pressure and air flowrate could not be decoupled, leading to over scavenging and increased short circuiting of fresh charge into the exhaust.]]></description>
      <pubDate>Tue, 30 Dec 2025 09:46:53 GMT</pubDate>
      <guid>https://trid.trb.org/View/2612402</guid>
    </item>
    <item>
      <title>Clean Cuts, Clear Conscience: Advanced Engines, Optimized Tools, Eco-Friendly Fuels</title>
      <link>https://trid.trb.org/View/2623956</link>
      <description><![CDATA[Handheld outdoor power equipment is utilized globally to shape and maintain the environment, serving as daily assistants in forestry under demanding conditions. In the power tool sector, the transition from petrol to battery-powered products is already well underway, particularly for consumer applications.However, internal combustion engines will continue to be indispensable for professional users of power tools, who place the highest demands on their equipment in terms of performance and energy density. These power tools are often used in remote locations and thus far away from a possible charging infrastructure. To contribute to climate protection, biofuels and RFNBOs are crucial.The continuous optimization of engine technology and its overall system, including cutting tools (such as saw chains and cutting wheels), is a key development goal for STIHL. The optimized interaction between the saw chain, guide bar, and power train is necessary for efficient work progress and ergonomic handling of the products during operation. Consequently, STIHL focuses on the overall system in design and development, supported by the in-house manufacturing of all critical components.The newly developed STIHL Hexa saw chain is an innovative system featuring a new tooth shape, representing a significant milestone. The Hexa sharpening pattern and narrow kerf enhance the cutting performance of the previous standard saw chain by up to ten percent. This improvement is clearly noticeable to professional users during felling, limbing, and cutting to length.The saw chain also remains sharp for a longer period and has an extended service life with optimal cutting performance. This means that the energy used is converted into work progress with higher efficiency.When combined with a highly efficient two-stroke engine and sustainable fuels, not only the energy consumption per cutting surface is reduced, but CO2e emissions are also significantly lowered. This comprehensive package contributes positively to climate protection during sequential timber harvesting.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623956</guid>
    </item>
    <item>
      <title>Effect of Plasma-Assisted Ignition on Combustion and Emission Characteristics of Two Stroke Engines with Different Fuels</title>
      <link>https://trid.trb.org/View/2623915</link>
      <description><![CDATA[This study explores the effect of plasma-assisted ignition (PAI) on combustion stability and emissions in two-stroke spark-ignition engines. Two engine platforms were evaluated: a conventional single-cylinder two-stroke engine and a thermodynamically advanced opposed-piston two-stroke (OP2S) engine. The OP2S engine configuration offers reduced heat loss and higher power density due to its uniflow scavenging and favorable geometry, but suffers from high residual gas fraction, which increases ignition difficulty and combustion instability. To address this, nanosecond-pulsed PAI was applied in various spatial arrangements and discharge voltages, using both gasoline and a low-reactivity gasoline/DMC blend fuel. Spark ignition timing was held constant at the minimum advance for best torque across all tests. Combustion stability was assessed via indicated mean effective pressure (IMEP) and its coefficient of variation, while CO and HC emissions were measured as environmental indicators. Results show that PAI significantly enhanced ignition stability, reducing COVIMEP by up to 84% and HC emissions by up to 24%, depending on fuel and engine type. The OP2S engine showed greater responsiveness to ignition configuration and plasma positioning due to its uniflow scavenging method. These findings confirm that PAI is a promising strategy for improving ignition robustness and emission performance in both conventional and advanced two-stroke engine architectures.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623915</guid>
    </item>
    <item>
      <title>Optimum Bore-to-Stroke Ratio for a Flathead Uniflow Two-Stroke SI Engine and its Impact on Different Fuels</title>
      <link>https://trid.trb.org/View/2623899</link>
      <description><![CDATA[This numerical study investigates a spark-ignited, two-stroke engine employing uniflow scavenging, flathead cylinder head design, and an exhaust valve system to identify the optimal bore-to-stroke (B/S) ratio for maximizing brake efficiency at fixed displacement. A single-cylinder prototype engine was constructed, and its experimental data validated a 1D GT-SUITE simulation model. This validated model was then utilized to simulate a full-scale, 1.5-liter displacement, horizontally opposed four-cylinder engine with supercharger-assisted boosting, intended for small aircraft propulsion. The simulations explored a range of B/S ratios from undersquare (0.7) to oversquare (1.5), maintaining a consistent brake power output of 60 kW at 3000 rpm and lambda 0.9. Results showed that increasing the B/S ratio enhanced brake efficiency from 26.0% at B/S=0.7 to 27.0% at B/S=1.5, largely due to reduced frictional losses attributed to shorter stroke and lower piston speeds, decreased heat transfer losses, and a modest reduction in compressor power demand. Frictional power decreased from 12.7 kW at B/S=0.7 to 9.6 kW at B/S=1.5, while heat transfer losses dropped from 43.5 kW to 40.6 kW respectively. Fuel analyses involving gasoline E27, ethanol (E100), and aviation gasoline (AvGas) revealed ethanol (E100) provided the highest brake efficiency yet increased fuel consumption (BSFC). AvGas presented the lowest BSFC, with gasoline E27 performing intermediately. A key finding is the inverse trend in heat transfer losses, where the undersquare configuration exhibited greater losses than those of the oversquare geometry, contrary to conventional expectations. Combined with improved mechanical efficiency due to reduced friction, the oversquare design emerged as the most efficient configuration. These findings challenge traditional heat transfer assumptions in common two and four-stroke engines and highlight the benefits of higher B/S ratios for improving overall performance in flathead uniflow two-stroke engines. The results will serve as the foundation for the design of the full-scale four-cylinder aeronautical engine.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623899</guid>
    </item>
    <item>
      <title>Development of Supercharged Direct-Injection Two Stroke Engine with Intake and Exhaust Valve for Series Hybrid (2nd Report)- To Realize Lean Burn -</title>
      <link>https://trid.trb.org/View/2623888</link>
      <description><![CDATA[The two-stroke engine, known for its small displacement and high performance, is space-efficient when installed in a vehicle. As such, incorporating two-stroke engines into HEVs is an effective way to reduce vehicle weight and optimize engine space. However, one downside is that the amount of unfired elements in the exhaust gas increases due to the air/fuel mixture being expelled into the exhaust system during the scavenging process. Moreover, combustion can become unstable due to the large volume of residual burned gases in the cylinder. To address these issues, we propose a two-stroke engine equipped with intake and exhaust valves that directly inject fuel into the cylinder.In our first report, we presented an engine design and method that enable high scavenging efficiency and stable combustion in a two-stroke engine [1]. In this second report, we share the results of our research aimed at improving fuel efficiency and achieving low emissions, all while maintaining the high performance typical of a two-stroke engine.To enhance fuel efficiency, the amount of burned gas was optimized by adjusting the timing and lifting the intake and exhaust valves. Lean combustion was achieved by leveraging the high temperature in the cylinder, utilizing its excellent ignitability. Additionally, it has been reported that THC emissions—a common issue in two-stroke engines—are reduced by preventing unburned gas from being expelled into the exhaust pipe through the adoption of in-cylinder direct injection.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:51 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623888</guid>
    </item>
    <item>
      <title>Performance Prediction of a Two-Stroke Aviation S.I. Engine by Means 0D/1D Thermo-Fluid Dynamic Simulation Code</title>
      <link>https://trid.trb.org/View/2623878</link>
      <description><![CDATA[Two-stroke engines represent an attractive solution for aviation industry applications (UAVs, VTOL aircraft, and ultralight aircraft) due to their compact size, high power-to-weight ratio, reduced number of moving parts, and the ability to operate with different fuels. This work presents a 0D/1D methodology for simulating the gas exchange, combustion, and unsteady flow of a two-stroke aviation engine. The scavenging and combustion processes, as well as the unsteady flow within the induction and exhaust systems, are investigated using a 0D/1D modeling approach. This study is motivated by the need to assess the accuracy of such models in predicting engine performance. For this purpose, the thermo-fluid dynamic code GASDYN has been applied and enhanced. The proposed 0D model is embedded into a 1D fluid-dynamic code for simulating the entire engine system. To characterize the baseline configuration, which includes tangential ports that facilitate a loop-scavenging process, computed results are compared with available experimental data from a conventional two-stroke spark ignition engine used in aviation applications. Validation was carried out under operating conditions representative of UAV operation at different speeds and full load. The final goal of this study is to modify the exhaust system geometry to increase the maximum power of the same engine architecture. Satisfactory results were achieved, demonstrating that the proposed approach can be applied to design and optimize two-stroke engines with a high degree of accuracy and reduced computational costs.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623878</guid>
    </item>
    <item>
      <title>Assessment of E-Fuels Applicability as Gasoline Replacement in a Small Two-Stroke Engine</title>
      <link>https://trid.trb.org/View/2623877</link>
      <description><![CDATA[The push for reducing greenhouse gas emissions has extended to various sectors, including outdoor power equipment. While electrification is a promising solution for low-power gardening tools, the substitution of small two-stroke engines becomes critical for applications requiring higher power and range. Biofuels and e-fuels produced from renewable sources present a viable short-term alternative, leveraging existing engine technologies to minimize dependence on fossil fuels. However, the ability of current engines to operate with these fuels while maintaining performance and emission levels without modifications requires thorough evaluation.This study investigates the feasibility of using e-fuels as sustainable alternatives to gasoline in small two-stroke engines. Preliminary computational fluid dynamics (CFD) simulations were conducted to evaluate the performance of the e-fuel after defining a proper fuel surrogate. Experimental tests were then carried out to assess combustion characteristics, engine performance, and pollutant emissions substituting a commercial E10 gasoline with the synthetic counterpart. The results demonstrate that e-fuels achieve comparable performance and emissions profiles to gasoline, indicating their potential as drop-in replacements for conventional fuels in existing engine technologies. These findings highlight the practicality and promise of e-fuels in advancing sustainable solutions for outdoor power equipment.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623877</guid>
    </item>
    <item>
      <title>Study of Combustion Characteristics of a Two-Stroke Opposed Piston Engine using Low-Octane Fuels</title>
      <link>https://trid.trb.org/View/2623863</link>
      <description><![CDATA[Various fuels are being considered as the next generation of carbon neutral fuels, including methanol, ethanol, and SAF. These have widely different ignition properties. Methanol and ethanol are high-octane fuels, so there are no major problems with their use in gasoline engines. However, SAF is a hydrocarbon with a large molecular weight, so it has a fundamentally low octane rating and is not easy to use in SI engines. In order to put carbon-neutral fuels of various properties into practical use, it is effective to develop a technology that allows fuels with low octane to be operated in SI engines. Therefore, in this study, basic research was conducted on the combustion of fuels with low octane using PRF fuel in opposed-piston engines. Opposed piston engines are characterized by their light weight due to the absence of a cylinder head, low S/V ratio due to the ultra-long stroke, reduced cooling loss due to the long stroke, and reduced vibration due to the offsetting of the reciprocating inertial forces of the left and right pistons, resulting in high efficiency and output. In addition, one of the disadvantages of low-octane fuel is that it tends to auto-ignite, but combustion under high residual gas conditions has the effect of suppressing fuel auto-ignition, and by using a 2-stroke engine with a high percentage and high concentration of residual gas and locally high temperatures, auto-ignition is suppressed and low The use of two-stroke engines with high residual gas content and high concentration and high local temperatures can be expected to suppress auto-ignition and allow the use of low-octane fuels.]]></description>
      <pubDate>Thu, 13 Nov 2025 16:12:50 GMT</pubDate>
      <guid>https://trid.trb.org/View/2623863</guid>
    </item>
    <item>
      <title>An Investigation into the Impact of Cylinder Count on the Efficiency
                    of Opposed Piston Two-Stroke Compression Ignition Engines</title>
      <link>https://trid.trb.org/View/2608392</link>
      <description><![CDATA[
                
                The gas exchange process of opposed piston two-stroke (OP2S) diesel engines is
                    primarily driven by the pressure differential between the intake and exhaust,
                    making them susceptible to cylinder-to-cylinder crosstalk, and therefore to
                    cylinder count. This study examined how cylinder count influences brake
                    efficiency in OP2S engines. Using an experimentally validated 1D engine model,
                    three architectures, ranging from two to four cylinders, were created and
                    simulated across their full operating ranges. To isolate the impact of cylinder
                    count, all configurations employed identical cylinder and port geometries, and
                    identical but scaled electrically assisted turbocharger based airpaths. The
                    engines were also controlled to consistent trapped conditions at a given
                    operating condition, resulting in comparable closed-cycle efficiencies.
                    Comparisons were then made using both scaled electrified airpaths and by
                    assuming isentropic airpath work, to assess the impact of airpath efficiency on
                    the results. With electrified airpaths, the two- and four-cylinder architectures
                    had approximately 4.1%rel and 2.2%rel lower brake
                    efficiencies, respectively, than the three-cylinder configuration on average.
                    Additionally, the three-cylinder engine was found to be less sensitive than the
                    other architectures to airpath efficiency, as on a per-cylinder basis it had up
                    to a 17% lower power requirement for the turbocharger compressor, and recovered
                    up to 3% less energy from the turbocharger turbine. These trends were also
                    present when assuming isentropic airpath work, with the magnitude of the
                    efficiency penalty of the two- and four-cylinder architectures reducing to
                        0.8%rel and 0.6%rel, respectively due to the lower
                    overall magnitude of airpath power requirements. In all cases, the dominant
                    contributor to the above results was the differing scavenging characteristics of
                    the engines due to cylinder-to-cylinder interactions, demonstrating that
                    cylinder count has a measurable impact on OP2S efficiency, and should be a key
                    factor in designing an efficient OP2S engine.
            ]]></description>
      <pubDate>Thu, 16 Oct 2025 12:01:31 GMT</pubDate>
      <guid>https://trid.trb.org/View/2608392</guid>
    </item>
    <item>
      <title>Computational analysis of piston shape effects on in-cylinder gas flow, fuel-charge mixing, and combustion characteristics in a two-stroke rod-less spark ignition opposed-pistons engine</title>
      <link>https://trid.trb.org/View/2589007</link>
      <description><![CDATA[Compared with the traditional in-cylinder direct-injection spark ignition engine, the side-injection and side-spark-ignition characteristics of the two-stroke opposed-piston engine increase the ignition kernel offset and flame propagation distance. Increasing the flame propagation speed can to some extent solve the drawbacks caused by the non-central arrangement of spark plugs. The combustion chamber structure plays a crucial role in gas flow, fuel-charge mixing, and combustion characteristics. Therefore, three pistons were designed and comparatively analyzed in this study. The results show that: The pancake piston is beneficial to maintaining the intake swirl strength due to its simple and smooth spherical arc structure. The swirl strength of the pit and pit-guided piston decreases obviously, and the tumble strength can be maintained well. Compared to pancake and pit-guided pistons, the average TKE for the pit piston increased by approximately 25%, with a more concentrated distribution at the spark timing. The pancake piston exhibits the best scavenging performance, reducing the residual exhaust gas ratio by 2.1% and fresh air loss by 3.3% to the pit piston. A stable ignition core can be formed at the spark timing, but significant differences are observed in the flame propagation process for three pistons. Compared to the pit-guided piston, the pit piston has a 0.3% decrease in the indicated thermal efficiency, but a 13.1% decrease in combustion duration, which reduces knock tendency.]]></description>
      <pubDate>Thu, 02 Oct 2025 11:35:54 GMT</pubDate>
      <guid>https://trid.trb.org/View/2589007</guid>
    </item>
    <item>
      <title>Effects of employing B24 biodiesel on marine two-stroke diesel engine through comprehensive evaluations of cylinder oils</title>
      <link>https://trid.trb.org/View/2586825</link>
      <description><![CDATA[The utilization of alternative fuels, such as biodiesel, plays a crucial role in reducing greenhouse gas emissions in maritime transportation. However, employing biodiesel potentially impacts the performance of engine critical components, thereby influencing the reliability of marine diesel engines. Therefore, this study first collected cylinder residual oils from a marine two-stroke diesel engine employing B24 biodiesel. Subsequently, cylinder residual oils were subjected to comprehensive tests, including oil ferrographic and spectroscopic analysis, rheology behavior, moisture testing, thermogravimetric properties, and insoluble analysis. The results indicate that the initial utilization of B24 biodiesel led to fuel compatibility and adaptability issues, resulting in fuel dilution of oils. In specific, the cleanliness and thermal stability of cylinder oils decreased, while the concentration of iron, vanadium, moisture, and insoluble in oils, and oil viscosity significantly increased, indicating increased engine wear during this stage. With prolonged utilization of B24 biodiesel, the cleanliness of cylinder oils increased, and other performance was also restored to normal levels compared to those of employing low sulfur fuel oil. These research findings demonstrate the adaptability of B24 biodiesel in marine diesel engines, also providing data support for the utilization of biodiesel in maritime applications.]]></description>
      <pubDate>Fri, 26 Sep 2025 13:39:56 GMT</pubDate>
      <guid>https://trid.trb.org/View/2586825</guid>
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