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Abstract Super duplex stainless steel (SDSS) is a type of stainless steel made of chromium (Cr), nickel (Ni), and iron (Fe). In the present work, a 1.6 mm wide thin sheet of SDSS is joined using gas tungsten arc welding (GTAW). The ideal parameter for a bead-on-plate trial is found, and 0.216 kJ/mm of heat input is used for welding. As an outcome of the welding heating cycle and subsequent cooling, a microstructural study revealed coarse microstructure in the heat-affected zone and weld zone. The corrosion rate for welded joints is 9.3% higher than the base metal rate. Following the corrosion test, scanning electron microscope (SEM) analysis revealed that the welded joint’s oxide development generated a larger corrosive attack on the weld surface than the base metal surface. The percentages of chromium (12.5%) and molybdenum (24%) in the welded joints are less than those in the base metal of SDSS, as per energy dispersive X-ray (EDX) analysis.

Abstract Recent legislations require very low soot emissions downstream of the particulate filter in diesel vehicles. It will be difficult to meet the new more stringent OBD requirements with standard diagnostic methods based on differential sensors. The use of inexpensive and reliable soot sensors has become the focus of several academic and industrial works over the past decade. In this context, several diagnostic strategies have been developed to detect DPF malfunction based on the soot sensor loading time. This work proposes an advanced online diagnostic method based on soot sensor signal projection. The proposed method is model-free and exclusively uses soot sensor signal without the need for subsystem models or to estimate engine-out soot emissions. It provides a comprehensive and efficient filter monitoring scheme with light calibration efforts.

Abstract The present study examines the effect of the multiple injection strategies in a common rail diesel engine using machine learning, image processing, and object detection techniques. The study demonstrates a novel approach of utilizing image-processing tools to gain information from heat release rates and in-cylinder visualizations from experimental or computational studies. The 3D CFD combustion and emission predictions of a commercial code ANSYS FORTE© are validated with small-bore common rail diesel engine data with known injection strategies. The validated CFD tool is used as a virtual plant model to optimize the injection schedule for reducing oxides of nitrogen (NOx) and soot emissions using an apparent heat release rate image-based machine learning tool. A methodology of the machine learning tool is quite helpful in predicting the NO–soot trade-off.

Abstract The European Union’s pro-ecological policy imposes a requirement to use biofuel additives in diesel fuel which is supposed to support the sustainable development of transport and limit its negative impact on the natural environment. The study presents an analysis of the exhaust gas components and the amount of solid particles carried out for internal combustion engines fueled with mixtures of diesel fuel and fatty acid methyl esters. Additionally, the computer software of the tested power units was modified by changing the amount of fuel to be supplied and the air intake. The goal of the tests was to find out how the fuel mixture and reprogramming of the computer control systems would impact the emission of exhaust gas components. Based on the tests, it was found that an additive of fatty acid methyl esters to diesel does have an influence on the tested unit parameters.

Abstract The ASTM D130 was first issued in 1922 as a tentative standard for the detection of corrosive sulfur in gasoline. A clean copper strip was immersed in a sample of gasoline for three hours at 50°C with any corrosion or discoloration taken to indicate the presence of corrosive sulfur. Since that time, the method has undergone many revisions and has been applied to many petroleum products. Today, the ASTM D130 standard is the leading method used to determine the corrosiveness of various fuels, lubricants, and other hydrocarbon-based solutions to copper. The end-of-test strips are ranked using the ASTM Copper Strip Corrosion Standard Adjunct, a colored reproduction of copper strips characteristic of various degrees of sulfur-induced tarnish and corrosion, first introduced in 1954. This pragmatic approach to assessing potential corrosion concerns with copper hardware has served various industries well for a century.

Abstract The use of data-driven algorithms for the integration or substitution of current production sensors is becoming a consolidated trend in research and development in the automotive field. Due to the large number of variables and scenarios to consider; however, it is of paramount importance to define a consistent methodology accounting for uncertainty evaluations and preprocessing steps, that are often overlooked in naïve implementations. Among the potential applications, the use of virtual sensors for the analysis of solid emissions in transient cycles is particularly appealing for industrial applications, considering the new legislations scenario and the fact that, to our best knowledge, no robust models have been previously developed.

Abstract Earlier studies have proven how ducted fuel injection (DFI) substantially reduces soot for low- and mid-load conditions in heavy-duty engines, without significant adverse effects on other emissions. Nevertheless, no comprehensive DFI study exists showing soot reductions at high- and full-load conditions. This study investigated DFI in a single-cylinder, 1.7-L, optical engine from low- to full-load conditions with a low-net-carbon fuel consisting of 80% renewable diesel and 20% biodiesel. Over the tested load range, DFI reduced engine-out soot by 38.1–63.1% compared to conventional diesel combustion (CDC). This soot reduction occurred without significant detrimental effects on other emission types. Thus, DFI reduced the severity of the soot–NOx tradeoff at all tested conditions.

Abstract Aluminum hybrid composites are driving a new trend in metal matrix composites for high strength-to-weight ratio applications such as the automotive industry (piston–cylinder, brakes, shafts), aircraft (engines, airframe), aerospace (space panels), and marine (body frame). Al 6061 is chosen as the matrix for its compatibility and excellent castability in the current work. The reinforcements were silicon carbide (SiC) of size 65μ and tungsten carbide (WC) of 3–5μ due to their enhancing mechanical and corrosion behavior with low density. Composites were prepared through stir casting using different quantities of SiC wt.% 10 and 15, while WC is 0–6% by weight in 2% increments. The results show that mechanical properties such as tensile strength and hardness enhanced due to the gradual strengthening of grains leads to high wear resistance. SEM images of tensile failure show that pits, voids, cracks, burrs, and grain fractures characterize composite failure.

Abstract The shot-to-shot variations in common rail injection systems are primarily caused by pressure wave oscillations in the rail, pipes, and injector body. These oscillations are influenced by fuel physical properties, injector needle movement, and pressure and suction control valve activations. The pressure waves are generated by pump actuation and injector needle movement, and their frequency and amplitude are determined by fluid properties and flow path geometry. These variations can result in cycle-to-cycle engine fluctuations. In multi-injection and split-injection strategies, the pressure oscillation from the first shot can impact the hydraulic characteristics of subsequent shots, resulting in variations in injection rate and amount. This is particularly significant when using alternative fuels such as biodiesel, which aim to reduce emissions while maintaining fuel atomization quality.

Abstract A rapid compression and expansion machine (RCEM) was used to experimentally investigate the ignition phenomena of dielectric-barrier discharge (DBD) in engine conditions. The effect of elevated pressure and temperature on ignition phenomena of a methane/air premixed mixture was investigated using a DBD igniter. The equivalence ratio was changed to elucidate the impact of DBD on flame kernel development. High-speed imaging of natural light and OH* chemiluminescence enabled visualization of discharges and flame kernel. According to experimental findings, the discharges become concentrated and the intensity increases as the pressure and temperature rise. Under different equivalence ratios, the spark ignition (SI) system has a shorter flame development time (FDT) as compared with the DBD ignition system.

Abstract To understand how the composition of novel lubricant additives and their ash interact with gasoline particulate filters (GPFs), an accelerated aging protocol was conducted using three lubricant additive formulations and two GPF types. The additive packages (adpaks) consisted of Ca+Mg detergent in a 3:1 or 0:1 ratio and an anti-wear component—either zinc dialkyl dithiophosphate (ZDDP) or a novel phosphonium-phosphinate ionic liquid (IL) substitute. The particulate sampling captured amount/compositions of particulate matter (PM) generated, total particulate number, and size distribution. Five ash loadings were completed. GPF position and adpak composition affected the backpressure, ash composition, ash morphology, and captured mass. The particulate sampling indicated that the ash component consisted primarily of particles less than 50 nm in size and that the Mg-only adpak resulted in more particulate of 50–400 nm in size.

Abstract Climate change and stringent emission regulations have become major challenges for the automotive sector, prompting researchers to investigate advanced combustion technologies. Gasoline compression ignition (GCI) technology has emerged as a potential solution, delivering higher brake thermal efficiency with ultra-low nitrogen oxides (NOx) and particulate emissions. Combustion stability and controls are some of the significant challenges associated with GCI. This study investigates the combustion characteristics of a two-cylinder diesel engine in GCI mode. GCI experiments were performed using a low-octane fuel prepared by blending 80% (v/v) gasoline and 20% (v/v) diesel (G80). Baseline experiments were conducted in conventional diesel combustion (CDC) mode. These experiments investigated the effects of double pilot injection, first pilot fuel ratio, and the start of main fuel injection timing (10–8°CA before top dead center, bTDC).

Abstract Internal combustion (IC) engines play an important role in the global economy by powering various transport applications. However, it is a leading cause of urban air pollution; therefore, new combustion strategies are being developed to control emissions. One promising advanced low-temperature combustion (LTC) technology is gasoline compression ignition (GCI). This experimental study assesses the performance of a two-cylinder engine, emissions, and exhaust particulate characteristics using G80 (80% v/v gasoline and 20% v/v diesel) blend operating in GCI mode vis-à-vis baseline conventional diesel combustion (CDC) mode using diesel. The effects of double pilot injection, Pilot-1 proportion (10–30%), and main injection timing were investigated on the GCI combustion. Experiments were performed at different engine loads (3, 4, and 5 bar brake mean effective pressure [BMEP]) at a constant engine speed (2000 rpm).

Abstract Personal watercraft (PWC) users and other high-speed watersports participants have sustained rectal and vaginal injuries during falls into the water, herein referred to as water intrusion injuries (WIIs). WIIs result from the rapid introduction of water into these lower body cavities causing injury to the soft tissues of the perineum, rectum, and vagina. While case studies of injured water-skiers and PWC users are reported in the literature, there is little information related to passenger kinematics and pressure exposure during a rearward fall from a PWC. The results of an experimental study of passenger falls from two “high-performance” PWC are presented herein. A human passenger was caused to fall rearward as the PWC was accelerated at maximum throttle starting from idle speed (≈3–4 mph) and planing speeds of ≈20–30 mph. The subject passenger fell from the aft seat position and while standing on the rear platform.

Abstract An experimental test bed study was conducted in a 3.8-liter diesel common rail engine with a gasoline port injection to evaluate the aftertreatment strategy in low- and high-reactive fuel. The selection of diesel oxidation catalyst (DOC) and precious group metal (PGM) content is critical for low-temperature combustion (LTC) (dual fuel) to control hydrocarbon (HC) and carbon monoxide (CO) emissions. Three DOCs with different PGM contents were tested along with different dual-fuel compositions to understand their effectiveness and particle mass composition. The chemical composition of exhaust particles from the engine out and DOC out are compared. An increase in low-reactive fuel (D15G85) and an increase in PGM content highlights a significant reduction in particle mass (PM) from 31 mg/kWhr to 2 mg/kWhr.

Abstract Reaching the particle emissions regulatory limits for the combustion engine is a challenge for developers. Particle filters have been the standard solution to reduce particle emissions, but filters are limited in storage capacity and need to be regenerated, a process emitting more carbon dioxide (CO2) as more fuel is consumed to regenerate the filter. In previous research, it was found that the engine can emit large spikes in particle numbers (PNs) under stationary operating conditions. These spikes were several orders of magnitude higher than for the base particle emissions level and occurred seemingly at random. The source of the spikes was believed to be the cylinder-piston-ring system and as 50–99% of the particles stemmed from these spikes, the influence on the particle emissions made it an interesting investigation to find the root cause of it. The experiments were performed for different piston ring loads, locked ring positions, and different oil compositions.

Abstract Heavy-duty (HD) engines for sale in the United States must be demonstrated to emit below allowable criteria and particulate emission limits over the operational load and speed cycle specified by the Federal Test Procedure (FTP) Heavy-Duty certification test. The inherently nonlinear load response of internal combustion engines tends to increase torque variability during the most dynamic portions of the test cycle. This clouds assessment of engine developments intended to improve transient performance and leads to frequent invalidation of certification tests. This work sought to develop and evaluate test torque control strategies that reduce this variability. Several load-control algorithms were evaluated for this purpose using a Cummins ISX15 HD diesel engine loaded with a transient alternating current (AC) dynamometer.

Abstract The Coordinating Research Council (CRC) is actively involved in developing and applying advanced analytical techniques to the chemical characterization of transportation fuels. This article complements a 2017 CRC project to quantify and compare the effects of a commercially available renewable diesel fuel (hydrotreated vegetable oil [HVO]) and an ultralow sulfur diesel (ULSD) fuel on engine-out gaseous and particulate matter (PM) emissions from a light-duty vehicle. Results showed that the combustion of HVO fuel had an advantage over ULSD in terms of lowering engine-out emissions (THC, CO, NOx, etc.). Furthermore, this advantage is strongly related to the fuel composition. This article summarizes the results of advanced and comprehensive analytical tests on the same ULSD and HVO fuels and attempts to connect some of the engine-out emissions results to fuel composition and specific chemical structures.

Abstract Gasoline direct-injection (GDI) engines are increasing market penetration. They are attractive because they substantially decrease CO2 emissions and can increase fuel economy. However, due to their design, GDI engines are prone to increases in soot production. Blends of alcohols with gasoline have been observed to decrease soot production in GDI engines. However, results have been mixed, with publications suggesting either a decrease or an increase in soot production. Recent publications have indicated that increases in soot production are tied to fuel impingement onto the cylinder head during high-load engine periods. The work presented here utilizes an equation of state (EoS) model to understand the volatility characteristics of oxygenate-surrogate fuel blends, focusing on the volatility of aromatics. EoS calculations are rapid, and allow for the simulation of a broad range of temperatures and pressures.

Abstract Ducted Fuel Injection (DFI) is a concept of growing interest to abate soot emissions in diesel combustion based on a small duct within the combustion chamber in front of the injector nozzle. Despite the impressive potential of the DFI proven in literature, its application for series production and the complexity for the adaptation of existing Compression-Ignition (CI) engines need to be extensively investigated. In this context, the aim of this study is to numerically assess the potential of DFI implementation in a CI engine for light-duty applications, highlighting the factors which can limit or facilitate its integration in existing combustion chambers. The numerical model for combustion simulation was based on a One-Dimensional/Three-Dimensional Computational Fluid Dynamics (1D/3D-CFD) coupled approach relying on a calibrated spray model, extensively validated against experimental data.