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Abstract In recent years, the use of cutting fluids has become crucial in hard metal machining. Traditional non-biodegradable cutting fluids have long dominated various industries for machining. This research presents an innovative approach by suggesting a sustainable alternative: a cutting fluid made from a blend of glycerol (GOL) and distilled water (DW). We conducted a thorough investigation, creating 11 different GOL and DW mixtures in 10% weight increments. These mixtures were rigorously tested through 176 experiments with varying loads and rotational speeds. Using Design-Expert software (DES), we identified the optimal composition to be 70% GOL and 30% DW, with the lowest coefficient of friction (CFN). Building on this promising fluid, we explored further improvements by adding three nanoscale additives: Nano-graphite (GHT), zinc oxide (ZnO), and reduced graphene oxide (RGRO) at different weight percentages (0.06%, 0.08%, 0.1%, and 0.3%).

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 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 This article presents a numerical solution to the problem of delamination in a separable Metal Composite High-Pressure Vessel (MC HPV). This problem is associated with local buckling of the inner metal shell (liner) surrounded by an outer rigid composite shell. A geometrically and physically nonlinear MC HPV deformation model is constructed considering the three-dimensional stress-strain state, real-time mode, and technological deviations inherent in real vessel designs. The model combines the deformation of the vessel end domes and the cylindrical part. A unilateral constraint is believed to exist on the interface between the liner and the composite shell, allowing the liner to delaminate from the latter when bending. Calculations are performed using the finite element method in the LS-DYNA software package in a dynamic formulation. The vessel is divided into solid finite elements such as TSHELL and SOLID.

Abstract A non-pneumatic tire (NPT) has a lot of applications and is a viable option for the future, as they do not possess the problem of blowouts and air pressure maintenance. In these NPTs, the air-filled part is replaced by a flexible structure capable of withstanding the weight of the vehicle and delivering optimum performance. In the present study, endeavors have been made to analyze the rolling performance of NPTs by considering a light commercial vehicle as an application. The NPTs with three different configurations are studied by considering three hyperelastic material models for the hexagonal spoke structure and shear band under various loading conditions. Initially, static analysis for the models is conducted in two dimension (2D) and three dimension (3D) to validate the results, and these models were further extended to rolling analysis. The rolling resistance and slip ratios are obtained and compared in both 2D and 3D analyses.

Abstract Knock has been studied by internal combustion engine researchers for well over a century. It remains perhaps the main limit on spark-ignition engine efficiency today. In an engine development environment, knock is typically described through quantification of the high-frequency signal content of cylinder pressure measurements. A cylinder pressure transducer gives a point measurement in the combustion chamber volume. In non-knocking combustion cycles, there is little pressure variation across the chamber; hence, this point measurement adequately represents the average gas pressure acting on the piston. This is not the case for knock where autoignition leads to strong pressure gradients and standing wave behavior or even supersonic shock wave propagation. The resulting pressure signal is complex to interpret.

Abstract The aim of this work is to present the results achieved in the evaluation of combustion metrics using low-cost sensors for the indirect measurement of cylinder pressure. The developed transducers are piezoelectric rings placed under the spark plugs. Tests were carried out on three different engines running in various speed and load conditions. The article shows the characteristics of the signals generated by the piezo-ring sensors, compared to those coming from laboratory-grade pressure transducers: focus is to assess the achievable accuracy in the determination of frequently used combustion metrics, such as those related to knock intensity (Maximum Amplitude of Pressure Oscillations, MAPO), combustion phasing (MFB10, MFB50, …), and peak pressure.

Abstract This research involves the study of the different properties of aluminum alloy (AA) 2024 in the presence of carbon nanotubes (CNTs) and Silicon (Si) nanoparticles. Structural morphology, elemental composition, mechanical properties (density, tensile strength, elongation, and hardness), and tribological properties (wear rate and coefficient of friction) of AA 2024 in the presence of CNTs, Si, and its combinations at various proportions were evaluated using a Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Analyzer (EDX), Universal Testing Machine (UTM), Model HMV-2T Vickers hardness test machine, and pin-on-disk friction-and-wear test rig. The Hybrid Metal Matrix Composite (HMMC) material is prepared by a two-stage stir casting method. It was found that the density of the AA 2024 + 4%CNT + 2%Si is 2.22 g/cm3, ultimate tensile strength is 308 N/mm2, elongation is 15.5%, and Vickers hardness is 187.5 Vickers Hardness Number (VHN).

Abstract In lean burn combustion, jet ignition is such a promising technology that is often used to improve the ignition and enhance combustion stability when ignition failure and misfire might occur. Four different orifice configurations are applied in the fueled prechamber and lean main chamber system to investigate the effect of orifice configurations on flame propagation and pressure oscillation. The combustion phases of jet ignition, pressure wave propagation, and mechanism of jet combustion with various orifice configurations considered are presented. In the present work, three phases of jet ignition propagation are observed. Besides, it is found that when the total orifice area is the same, the single-orifice configuration presents the fastest flame propagation and pressure oscillation. The viscosity effect and interactions between jet flows in multi-orifice configurations account for this phenomenon.

Abstract Aluminum Metal Matrix Composite (AMMC) materials have loftier individualities and are known as an alternative material for a range of aerospace and automotive engineering applications. Reinforcement inclusion makes the components tougher, resulting in low performance of machining by traditional conservative machining practices. The present study presents a detailed review of the machinability of AMMC (Pure Aluminum + Graphene nanoplatelets) using Wire Electric Discharge Machining (WEDM). For WEDM of AMMC, a multi-objective optimization method is proposed to evaluate possible machining parameters in order to achieve better machining efficiency. Taguchi’s approach to the design of experiments is used to organize the experiments. For performing experiments, an L27 orthogonal array was selected. Five input process variables were considered for this study. The Grey Relational Analysis (GRA) is used to achieve the best features of multi-performance machining.

Abstract An experiment has been developed to investigate the passive pre-chamber jet ignition process in gasoline engine configurations and low-load operating conditions. The apparatus adopted a modified 4-cylinder 2.0L gasoline engine to enable single-cylinder operation. To reduce the complexity, the piston position was fixed at a predefined position relative to the top dead center (TDC) to simulate thermodynamic conditions at ignition and injection timings. High-speed Infrared (IR) imaging was applied to visualize the jet penetration and ignition process inside the main cylinder and to investigate the cyclic spatial variability. Two passive pre-chambers with different total nozzle areas and numbers of nozzles were used. In addition, the pre-chamber volume and pressure at ignition timing were varied to examine their effect on jet ignition performance.

Abstract Passengers would always like to reach their destinations with minimum commute time. Generating a higher thrust is a necessity. This implies that the turbomachinery associated with the power plant has to rotate faster and with higher efficiencies. However, high rotational speeds, mainly in the transonic regime, often lead to boundary layer separation, shocks, compressor stall, and surge. The current investigation is an attempt to reduce the abovementioned phenomena. It involves the performance study of a smoothened controlled diffusion airfoil (CDA) blade that has been optimized by “Multi-Objective Genetic Algorithm” (MOGA) by altering maximum camber location and stagger angle. Inlet pressure is varied from 15 kPa to 30 kPa and the angle of attack ranging from 40.4° to 56.4°. C48-S16-BS1 is validated and considered as the baseline profile, and all other blades are collated to this.

Abstract TOC

Abstract Gasoline particulate filters (GPFs) are important aftertreatment components that enable gasoline direct injection (GDI) engines to meet European Union (EU) 6 and China 6 particulate number emissions regulations for nonvolatile particles greater than 23 nm in diameter. GPFs are rapidly becoming an integral part of the modern GDI aftertreatment system. The Active Exhaust Tuning (EXTUN) Valve is a butterfly valve placed in the tailpipe of an exhaust system that can be electronically positioned to control exhaust noise levels (decibels) under various vehicle operating conditions. This device is positioned downstream of the GPF, and variations in the tuning valve position can impact exhaust backpressures, making it difficult to monitor soot/ash accumulation or detect damage/removal of the GPF substrate. The purpose of this work is to present a unique example of subsystem control and diagnostic architecture for an exhaust system combining GPF and EXTUN.

Abstract Piston internal combustion engines used in the propulsion of ultralight aircraft are characterized by special operating conditions, especially an increased engine oil temperature. Most of the engines intended for the drive of the propeller drivetrain are air cooled. Failure to introduce an additional cooling agent so as to absorb and remove heat from the running engine makes the average lubricating oil temperature rise to about 140°C in the pistohn ring part. With such a thermal load, changes in the moments of resistance to motion of the engine are difficult to determine in the conditions of engine tests due to difficulties in temperature stabilization. The performance of aircraft engines requires taking into account many variables that are difficult to determine, which may affect changes in the moment of resistance to movement of the engine, especially when using oils of low dynamic viscosity.

Abstract High fuel injection pressure systems for Gasoline Direct Injection (GDI) engines have become widely used in passenger car engines to reduce emissions of particulates and pollutant gases. Current commercial systems operate at pressures of up to 450 bar, but several studies have examined the use of injection pressures above 600 bar, and some have even used pressures around 1500 bar. These works revealed that high injection pressures have numerous benefits including reduced particulate emissions, but there is still a need for more data on the possible benefits of injection pressures above 1000 bar. This article presents spray and engine data from a comprehensive study using several measurement techniques in a spray chamber and optical and metal engines. Shadowgraph imaging and Phase Doppler Interferometry (PDI) were used in a constant volume chamber to interpret spray behavior. Particle Image Velocimetry (PIV) was used to capture near-nozzle air entrainment.

Abstract Using an ultrasonic-assisted stir casting method, a pure aluminum (Al) matrix (99% purity) was mixed with Graphene Nanoplatelets (GNPs) in various proportions ranging from 0.5 wt.% to 2.0 wt.% to create a Metal Matrix Composite. The microstructural and mechanical behavior of pure Al-graphene composites were studied experimentally, and it was discovered that Al with 1.0 wt.% graphene composite exhibits improved mechanical properties, with a 38.80% increase in tensile strength and a 56.07% increase in microhardness. Furthermore, field-emission scanning electron microscope (FESEM) and transmission electron microscope (TEM) were used to inspect the composites’ exterior morphology, and fractography of the tensiled composites, as well as X-ray diffraction (XRD) analysis, was used to observe the materials’ stage changes.

Abstract Environmental protection and the depletion of nonrenewable energy sources necessitate the search for the replacement of, among others, diesel fuel (Df) in diesel engines with renewable fuel without major structural changes. For this reason, vegetable oils are of interest as a possible fuel for this type of engine. Unfortunately, the physicochemical properties of vegetable oils differ significantly from Df. In addition to the boiling and freezing points, these properties include viscosity, density, and surface tension as well as wetting properties. For this reason, an attempt was made to modify these properties by adding n-hexane (Hex) and ethanol (Et) to canola oil (Co). The viscosity, density, surface tension, and wetting properties of Hex and Et are significantly different from those for Co.

Abstract Combining ball milling with stir casting in the synthesis of nanocomposites is found effective in increasing the strength and ductility of the nanocomposites. In the first step, the nanoparticles used as reinforcement are generated by milling a mixture of aluminum (Al) and manganese dioxide (MnO2) powders. A mixture of Al and MnO2 powders are mixed in the ratio of 1:2.4 by weight and milled at 300 rpm in a high-energy planetary ball mill for different durations of 120 min, 240 min, and 360 min to generate nano-sized alumina (Al2O3) particles. It is supposed that the powders have two different roles during milling, firstly, to generate nano-sized Al2O3 by oxidation at the high-energy impact points due to collision between Al and MnO2 particles, and secondly, to keep nano-sized Al2O3 particles physically separate by the presence of coarser particles.