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Surface coatings are one of the most widely used routes to enhance the tribological properties of cylinder kits due to effective sealing capability with low friction coefficient and high wear resistance. In the current study, we have conducted the surface texture characterization of the coating on piston skirts and evaluated the impact of a novel Abradable Powder Coating (APC) on cylinder-kit performance in comparison to stock pistons. The surface texture and characteristic properties varying across the piston skirt are obtained and analyzed via a 3D optical profiler and OmniSurf3D software. The engine operating conditions are found through a combination of measurements, testing, and a calibrated GT-Power model. The variable surface properties along with other dimensions, thermodynamic attributes, flow characteristics and material properties are used to build a model in CASE (Cylinder-kit Analysis System for Engines)- PISTON for both an APC coated piston and a stock piston.

Understanding cylinder-kit tribology is pivotal to durability, emission management, reduced oil consumption, and efficiency of the internal combustion engine. This work addresses the understanding of the fundamental aspects of oil transport and combustion gas flow in the cylinder kit, using simulation tools and high-performance computing. A dynamic three-dimensional multi-phase, multi-component modeling methodology is demonstrated to study cylinder-kit assembly tribology during the four-stroke cycle of a piston engine. The percentage of oil and gas transported through different regions of the piston ring pack is predicted, and the mechanisms behind this transport are analyzed. The velocity field shows substantial circumferential flow in the piston ring pack, leading to blowback into the combustion chamber during the expansion stroke.

Cylinder-kit tribology has been a significant focus in developing internal combustion engines of lower emission, reduced friction and oil consumption, and higher efficiency. This work addresses the impact of ring-groove geometry on oil (liquid oil and oil vapor) transport and combustion gas flow in the cylinder kit, using a dynamic three-dimensional multiphase modeling methodology during the four-stroke cycle of a piston engine. The ring and groove geometry, along with the temperature and pressure conditions at the interface between piston and liner, trigger the oil and gas (combustion gases and oil vapor) transport. A study of the second ring dynamics is presented to investigate the effect of negative ring twist on the three-dimensional fluid flow physics. The oil (liquid oil and oil vapor) transport and combustion gas flow processes through the piston ring pack for the twisted and untwisted geometry configurations are compared.

This paper presents a review of the core functions and decisions of transportation and traffic management in the automobile industry. Its purpose is to present the concepts within a revised framework which is set in a logistical channels context. Using this approach it easier to see the interdependence which is necessary between shippers and carriers that handle raw materials, component parts, and finished products.

Camless Variable Valve Actuation (VVA) technologies have been known for improving fuel economy, reducing emissions, and enhancing engine performance. VVA can be divided into electro-magnetic, electro-hydraulic, and electro-pneumatic actuation. A family of camless VVA designs (called LGD-VVA or Gongda-VVA) has been presented in an earlier SAE publication (SAE 2007-01-1295) that consists of a two-spring actuation, a bypass passage, and an electrohydraulic latch-release mechanism. The two-spring pendulum system is used to provide efficient conversion between the moving mass kinetic energy and the spring potential energy for reduced energy consumption and to be more robust to the operational temperature than the conventional electrohydraulic actuation; and the electrohydraulic mechanism is intended for latch-release function, energy compensation and seating velocity control.

The sole purpose of combustion in a piston engine is to generate pressure in order to push the piston and produce work. Pressure diagnostics provides means to deduce data on the execution of the exothermic process of combustion in an engine cylinder from a measured pressure profile. Its task is that of an inverse problem: evaluation of the mechanism of a system from its measured output. The dynamic properties of the closed system in a piston engine are expressed in terms of a dynamic stage - the transition between the processes of compression and expansion. All the phenomena taking place in its course were analyzed in the predecessor of this paper, SAE 2002-01-0998. Here, on one hand, its concept is restricted to the purely dynamic effects, while on the other, the transformation of system components, taking place in the course of the exothermic chemical reaction to raise pressure, are taken into account by the exothermic stage.

An auxiliary fueled prechamber ignition system can be used in an IC engine environment to provide lean limit extension with minimal cyclic variability and low emissions. Geometry and distribution of the prechamber orifices form an important criterion for performance of these systems since they are responsible for transferring and distributing the ignition energy into the main chamber charge. Combustion performance of nozzles with a single jet, dual diverging jets and dual converging jets for a methane fueled prechamber ignition system is evaluated and compared in a rapid compression machine (RCM). Upon entering the main chamber, the dual diverging jets penetrate the main chamber in opposite directions creating two jet tips, while the dual converging jets, after exiting the orifices, converge into a single location within the main chamber. Both these configurations minimize jet-wall impingement compared to the single jet.

Elastohydrodynamic lubrication, piston dynamics and friction are important characteristics determining the performance and efficiency of an internal combustion engine. This paper presents a finite element analysis on a production piston of a gasoline engine performed using commercial software, the COSMOSDesignStar, and a comprehensive cylinder-kit simulation software, the CASE, to demonstrate the advantages of using a reduced, parameterized model analysis in the assessment of piston design characteristics. The full piston model is parameterized according to the CASE specifications. The two are analyzed and compared in the COSMOSDesignStar, considering thermal and mechanical loads. The region of interest is the skirt area on the thrust and anti-thrust sides of the piston.

The fluid motion inside the engine cylinder is transient, three-dimensional and highly turbulent. It is also well known that cycle-to-cycle flow variations have a considerable influence on cycle-to-cycle combustion variations. Laser-based diagnostic techniques, for example, particle image velocimetry (PIV) or molecular tagging velocimetry, can be used to measure two or three components of the velocity field simultaneously at multiple locations over a plane. The use of proper orthogonal decomposition (POD) allows quantification of cycle-to-cycle flow variations, as demonstrated using PIV data [1]. In the present work, POD is used to explore the cycle-to-cycle flow variations utilizing molecular tagging velocimetry data. The instantaneous velocity fields were obtained over a swirl measurement plane when engine was operated at 1500 rpm and 2500 rpm.

Piston temperature plays a major role in determining details of fuel spray vaporization, fuel film deposition and the resulting combustion in direct-injection engines. Due to different heat transfer properties that occur in optical and all-metal engines, it becomes an inevitable requirement to verify the piston temperatures in both engine configurations before carrying out optical engine studies. A novel Spot Infrared-based Temperature (SIR-T) technique was developed to measure the piston window temperature in an optical engine. Chromium spots of 200 nm thickness were vacuum-arc deposited at different locations on a sapphire window. An infrared (IR) camera was used to record the intensity of radiation emitted by the deposited spots. From a set of calibration experiments, a relation was established between the IR camera measurements of these spots and the surface temperature measured by a thermocouple.

Combustion studies were completed using an International VT275-based, optical DI Diesel engine fueled with Diesel fuel, a Canola-derived FAMES biodiesel, as well as with a blend of the Canola-derived biodiesel and a cetane-reducing, oxygenated fuel, Di-Butyl Succinate. Three engine operating conditions were tested to examine the combustion of the fuels across a range of loads and combustion schemes. Pressure data and instantaneous images were recorded using a high-speed visible imaging, infrared imaging, and high-speed OH imaging techniques. The recorded images were post processed to analyze different metrics, such as projected areas of in-cylinder soot, OH, and combustion volumes. A substantially reduced in-cylinder area of soot formation is observed for the Canola-DBS blended fuel with a slight reduction from the pure FAMES biodiesel compared to pump Diesel fuel.

A multicomponent droplet evaporation model which discretizes the one-dimensional mass and temperature profiles inside a droplet with a finite volume method has been developed and implemented into a large-eddy simulation (LES) model for spray simulations. The LES and multicomponent models were used along with the KH-RT secondary droplet breakup model to simulate realistic fuel sprays in a closed vessel. The effect of various spray and ambient gas parameters on the liquid penetration length of different single component and multicomponent fuels was investigated. The numerical results indicate that the spray penetration length decreases non-linearly with increasing gas temperature or pressure and is less sensitive to changes in ambient gas conditions at higher temperatures or pressures. The spray models and LES were found to predict the experimental results for n-hexadecane and two multicomponent surrogate diesel fuels reasonably well.

Three-dimensional transient simulations using KIVA-3V were conducted on a 4-stroke high-compression ratio, methanol-fueled, direct-injection (DI) engine. The engine had two intake ports that were designed to impart a swirling motion to the intake air. In some cases, the intake system was modified, by decreasing the ports diameter in order to increase the swirl ratio. To investigate the effect of adding shrouds to the intake valves on swirl, two sets of intake valves were considered; the first set consisted of conventional valves, and the second set of valves had back shrouds to restrict airflow from the backside of the valves. In addition, the effect of using one or two intake ports on swirl generation was determined by blocking one of the ports.

As the variable nozzle turbine(VNT) becomes an important element in engine fuel economy and engine performance, improvement of turbine efficiency over wide operation range is the main focus of research efforts for both academia and industry in the past decades. It is well known that in a VNT, the nozzle endwall clearance has a big impact on the turbine efficiency, especially at small nozzle open positions. However, the clearance at hub and shroud wall sides may contribute differently to the turbine efficiency penalty. When the total height of nozzle clearance is fixed, varying distribution of nozzle endwall clearance at the hub and shroud sides may possibly generate different patterns of clearance leakage flow at nozzle exit that has different interaction with and impact on the main flow when it enters the inducer.

Numerical simulations of lean Methanol combustion in a four-stroke internal combustion engine were conducted on a high-compression ratio engine. The engine had a removable integral injector ignition source insert that allowed changing the head dome volume, and the location of the spark plug relative to the fuel injector. It had two intake valves and two exhaust ports. The intake ports were designed so the airflow into the engine exhibited no tumble or swirl motions in the cylinder. Three different engine configurations were considered: One configuration had a flat head and piston, and the other two had a hemispherical combustion chamber in the cylinder head and a hemispherical bowl in the piston, with different volumes. The relative equivalence ratio (Lambda), injection timing and ignition timing were varied to determine the operating range for each configuration. Lambda (λ) values from 1.5 to 2.75 were considered.

A three-dimensional piston ring model has been developed using finite element method with eight-node hexahedral elements. The model predicts the piston ring conformability with the cylinder wall as well as the separation gap between the interfaces if existing in the radial direction. In addition to the radial interaction between the ring front face and the cylinder wall, the model also predicts the contact between the ring and groove sides in the axial direction. This means, the ring axial lift, ring twist, contact forces with the groove sides along the circumferential direction are all calculated simultaneously with the radial conformability prediction. The ring/groove side contact can be found for scraper ring at static condition, which is widely used as the second compression ring in a ring pack. Thermal load is believed having significant influence on the ring pack performance.

A direct-injection and spark-ignition single-cylinder engine with optical access to the cylinder was used for the combustion visualization study. Gasoline and ethanol-gasoline blended fuels were used in this investigation. Experiments were conducted to investigate the effects of fuel injection pressure, injection timing and the number of injections on the in-cylinder combustion process. Two types of direct fuel injectors were used; (i) high-pressure production injector with fuel pressures of 5 and 10 MPa, and (ii) low-pressure production-intent injector with fuel pressure of 3 MPa. Experiments were performed at 1500 rpm engine speed with partial load. In-cylinder pressure signals were recorded for the combustion analyses and synchronized with the high-speed combustion imaging recording. Visualization results show that the flame growth is faster with the increment of fuel injection pressure.

The present communication reports on processing and interpreting velocity measurements in the wake of a cooling fan. Velocity data are typically phase averaged to create statistics that would be observed in a rotating frame of reference. The difference between any given instantaneous measurement and the phase mean value is often referred to as the fluctuating component of velocity. These deviations can be caused by a variety of mechanisms (blade vibration for example) and do not necessarily represent “turbulence”. A different approach using an eigenfunction decomposition of the data is used on a sample data set to help distinguish between cycle-to-cycle variations and turbulence.

LiDAR sensors are common in automated driving due to their high accuracy. However, LiDAR processing algorithm development suffers from lack of diverse training data, partly due to sensors’ high cost and rapid development cycles. Public datasets (e.g. KITTI) offer poor coverage of edge cases, whereas these samples are essential for safer self-driving. We address the unmet need for abundant, high-quality LiDAR data with the development of a synthetic LiDAR point cloud generation tool and validate this tool’s performance using the KITTI-trained PIXOR object detection model. The tool uses a single camera raycasting process and filtering techniques to generate segmented and annotated class specific datasets.

The paper is based on the premise that the sole purpose of combustion in piston engines is to generate pressure for pushing the expansion process away from the compression process (both expressed in terms of appropriate polytropes) to create a work producing cycle. This essential process, referred to as the dynamic stage of combustion, is carved out of the cycle and its salient properties deduced from the measured pressure profile, as a solution of an inverse problem: deduction of information on an action from its outcome. An analytical technique, construed for this purpose, is first presented and, then, applied to a direct injection, spark-ignition, methanol fueled four-stroke engine.