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The 3D CFD method has become an essential and reliable tool for the development of modern large gaseous-fuelled engines. This holds especially true for the optimization of mixture formation and charge motion in prechamber engines to ensure suitable conditions near the spark plug at ignition time. In order to initialize a quick combustion process, an ignitable mixture with high turbulence but moderate velocity must prevail round the spark plug. However, suitable models for combustion and heat transfer are inevitable for a realistic simulation of the whole engine cycle. Within 3D CFD codes the combustion process is usually calculated using the PDF (probability density function) - model; heat transfer is modeled based on the logarithmic wall function. Experimental investigations were carried out on a single cylinder research engine in order to validate the combustion model used and different heat transfer models.

The increasing use of natural gas as a vehicle fuel has generated considerable research activity to characterize the performance of engines utilizing this fuel. A light duty prechamber diesel engine was run under naturally aspirated and turbocharged CNG- Diesel dual fuel mode at four engine speeds 1100, 1400, 1700 and 2000 rpm. The maximum percentage of CNG substitution continues up to the engine knock limited power. The experimental results indicate a fall in brake power under naturally aspirated CNG-Diesel dual fuel mode compared to neat diesel operation. It was due to decrease in volumetric efficiency and slower combustion. Although turbocharged dual fuel operation shows an increase in brake power as well as an improvement in brake specific energy consumption as it provides a better air/fuel mixing and improves the homogeneous natural gas/air charge.

The FSAE is a world-renowned competition, in which students from across the globe compete against each other. The chassis is the main framework of the car, which is inherently responsible for accommodating all the components. The chassis is broadly classified into two types—monocoque and spaceframe. The FSAE chassis is of spaceframe type. The chassis also provides structural rigidity to the body of the car. It was observed through literature study that very minimal amount of research has been done on analyzing and validating the chassis by applying the different meshing techniques, namely 1D, 2D, and 3D. The mesh quality is very essential to obtain precise results and hence, effective methods for creating the mesh have been dealt with in this article. This study is on new investigations on different meshing techniques that can be implemented on an FSAE chassis.

Current developments in fuels and emissions regulations are resulting in an increasingly severe operating environment for diesel fuel injection systems. The formation of deposits within the holes or on the outside of the injector nozzle can affect the overall system performance. The rate of deposit formation is affected by a number of parameters, including operating conditions and fuel composition. For the work reported here an accelerated test procedure was developed to evaluate the relative importance of some of these parameters in a high pressure common rail fuel injection system. The resulting methodology produced measurable deposits in a custom-made injector nozzle on a single-cylinder engine. The results indicate that fuels containing 30%v/v and 100% Fatty Acid Methyl Ester (FAME) that does not meet EN 14214 produced more deposit than an EN590 petroleum diesel fuel.

Experimental investigations were carried out on the machinable wax filament using the fused deposition modelling (FDM) rapid prototyping process. The printer used for conducting the experiments was Flash Forge guider 2. The filament material used for this study was machinable wax filament of 1.75 mm diameter. Experimental trials were carried out as per Taguchi L9 orthogonal array to determine the optimum process parameter combination. The dimensional analysis of test samples were carried out in terms of change in volume of samples which is result of combine effect of deviations in all the dimensions of test sample. Four factors each at three levels was used to obtain the optimum printing parameters for better dimensional accuracy and proper printing. The four important printing parameters were taken as factor and set to analyse the significant factor affecting on printing. The complexity in printing of wax filament is taken in to consideration during the experimental study.

Currently, alternative fuels produced from waste resources are gaining much attention to replace depleting fossil fuels. The disposal of waste plastic poses severe environmental problems across the globe. The energy embodied in waste plastics can be converted into liquid fuel by pyrolysis. The present work explores the possibility of utilizing waste plastic oil (WPO) produced from municipal plastic wastes and waste cooking oil (WCO) biodiesel produced from used cooking oil in a dual fuel reactivity-controlled compression ignition (RCCI) mode. A single-cylinder light-duty diesel engine used for agricultural water pumping applications is modified to run in RCCI through suitable intake and fuel injection systems modifications. Alternative fuel blends, viz. WPO and WCO biodiesel with 20 vol. % in gasoline and diesel is used as a port and direct-injected fuels in RCCI. The premixed ratio and direct-injected fuel timings are optimized to achieve maximum thermal efficiency.

In order to increase the efficiency of internal combustion engines, Schaeffler Technologies recognized that it is necessary to identify the sources of energy losses, quantify such losses and to study ways to minimize them. Based on this premise, the Front End Accessory Drive parameters had to be investigated to locate where further potential enhancement is hidden. This paper aims to analyze and discuss about the main sources of energy losses occurring in FEAD and propose ways to optimize the system to the optimal range of efficiency and durability. Investigations showed that there are some loss points of the basic belt drive components which have good potential to be reducible, e.g., losses at bearings and belt.

The Cottonseed biodiesel combustion, sound and vibrations have been evaluated in a medium duty single cylinder DI engine (1.1L/cyl) by comparison with s ULSD#2 reference values. The engine was supercharged and had 20% EGR and all tests were conducted at 1400 rpm and at 4 bar BMEP load. Cylinder pressure was determined using a Kistler piezoelectric transducer. Combustion pressures peaked at 76 bar for both fuels. Ignition delay for CS100 decreased by 0.16 ms when compared to the ULSD#2 baseline. This would lead to a 23% lower peak heat release rate when operating CS100. The pressure rise rate for CS100 was 20% lower than ULSD#2, which related to the reduced ringing intensity for the biodiesel. The sound and vibrations were measured using a B&K condenser type multi-field microphone, and a tri-axial, piezoelectric accelerometer. All noise & vibration signals were analyzed with CPB and FFT Analysis, and Crank Angle Domain Analysis with B&K Pulse Platform software.

Modern concepts of downsized DI gasoline engines set up high requirements on the injection system to meet the emission targets. The fundamental knowledge and understanding of spray propagation physics are essential for the development of nozzles and injection strategies, due to reduced displacements in combination with the continuing trend of elevated fuel pressures. A detailed analysis of micro- and macroscopic spray parameters was carried out using a multihole solenoid driven DI injector. The measurements were performed in a continuously scavenged pressure chamber with full optical access. Fuel pressure up to 38MPa and backpressures in a range from 0.03 - 0.2 MPa were varied. Optical investigations were done by Shadowgraphy imaging and Phase Doppler Anemometry. The combination of micro- and macroscopic spray results are used to discuss the propagation behaviour of gasoline spray.

Good lighting is crucial for safe driving at night. Unfortunately, many parameters are contributing to the final result of the individual tolerances of car body, dynamics and headlamp: the resulting aim. The paper will analyze individual tolerance contributors from car body parameters like load, tire pressure, suspension as well as temperature parameters of chassis and plastic parts. The investigation shows that the headlight aim can fluctuate in a worst case scenario more than ±0.3°.

Computational fluid dynamics is used with the aim to gain further insights of the hydrogen injection process in internal combustion engines. To this end, three-dimensional RANS simulations of hydrogen under-expanded jets under a variety of injection pressures and temperatures and chamber backpressure are performed. A numerical framework that accounts for real-fluid effects is used which includes accurate non-linear mixing rules for thermodynamic and transport properties with multiple species. Jet formation process, transition to turbulent regime, and mixing process are investigated which are key aspects for the design of efficient injection and combustion. Different simulations are discussed to investigate the structures in the near field, such as Mach disk, barrel, and reflected shocks. It is found that for direct injection applications, especially in high back-pressure cases, accounting for real fluid behavior of hydrogen-air mixtures is important for accurate predictions.

In this paper we have obtained real-time series of in-cylinder pressure by carrying out some experiments and studied the in-cylinder pressure cycle-to-cycle variations in a diesel engine. By using recurrence plot (RP) and recurrence quantification analysis (RQA), we have investigated the dynamical characteristics of combustion in diesel engine through the in-cylinder pressure cycle-to-cycle variations. The results show that the combustion process exhibits many chaotic features and deterministic nature, the qualitative and quantitative change in combustion can be easily related to patterns in recurrence plots (RPs) and RQA, and combustion system is sensitive to initial conditions. The conclusions of our research work may be helpful in developing effective control strategies to improve diesel engine performance.

Requirements for constant track and camber have a much greater priority with commercial vehicles than on passenger cars. The target can be reached by a concept of rigid wheel suspension elements. It may cause some problems due to structural noise (vibration transfer). However, on commercial vehicles with elastic suspended driver cabs the noise transfer problem is considered to be manageable by suitable cab suspension elements, on buses a compromise in the tuning has to be found regarding overall damping.

As for a possible future vehicle, several types of roadable aircrafts have been studied recently. In this paper, a compact type roadable aircraft with a fixed ring wing is investigated. When a roadable aircraft is driven on road, its dimension has to be restricted by the Road Traffic Act, which indicates that the wing cannot be large. In flight, an enough wing size is needed to keep the weight and takeoff. One possible solution to solve this antinomy is an inflatable wing. In order to prove a possibility of an inflatable ring wing, the deformation of a ring wing and the aerodynamics characteristics are investigated. The FEM simulations are performed to examine the deformation of an inflatable ring wing by using ANSYS and MARC. The influences of deformations of a ring wing upon lift and drag are clarified by numerical simulation with the use of a commercial CFD code, SCRYU/Tetra.

The engine is the most important source of noise and vibration in a passenger car. Together with the oil pan the engine block in general radiates more than 50% of the total engine noise. Additionally structure-borne noise is transferred from the block through the engine mounts into the car body. All design features, which influence the structural integrity of the engine block, will therefore have an impact on the customer perceived noise and vibration behaviour of the vehicle. In order to develop an engine block towards a good noise and vibration performance, the first design decisions at the begin of a new engine programme should support this goal. This will facilitate the further development later on. This paper outlines some possibilities of computation and a testing method applicable in an advanced phase to evaluate different engine block design features without having either the complete engine or even the final design of the engine block.

Investigations have been carried out on low heat rejection engine(LHR) consisting of 3.2mm air gap insulated piston with superni(a low thermal conductivity nickel alloy material) crown and 3.2mm air gap insulated liner with superni insert by using alternate fuels viz. carbureted methanol and crude jatropha oil at varied injection pressured. Methanol is inducted through variable carburetor jet at different percentages of diesel flow rate by mass basis, installed at the inlet manifold of the engine during suction stroke and vegetable oil is injected through injector. LHR engine with carbureted methanol and crude jatropha oil showed improved performance and decreased pollution levels in comparison with conventional engine with pure diesel fuel and the performance is further improved with the increase of injection pressure with dual fuel operation.

In the course of the last few years a continuous increase of the injection pressure level of gasoline direct injection systems appeared. Today's systems use an injection pressure up to 200bar and the trend shows a further increase for the future. Although several benefits go along with the increased injection pressure, the disadvantages such as higher system costs and higher energy demand lead to the question of the lowest acceptable injection pressure level for low cost GDI combustion systems. Lowering injection pressure and costs could enable the technological upgrading from MPFI to GDI in smaller engine segments, which would lead to a reduction of CO2 emission. This publication covers the investigation of a low pressure GDI system (LPDI) with focus on small and low cost GDI engines. The influence of the injection pressure on the fuel consumption and emission behavior was investigated using a 1.4l series production engine.

A cycle-resolved test system was designed in a Two Stage Direct Injection (TSDI) Gasoline engine to simulate the engine quick start process in an Integrated Start and Generator (ISG) Hybrid Electric Vehicle (HEV) system. Based on the test system, measurement of the in cylinder HC concentrations near the spark plug under different engine coolant temperature and cranking speed conditions were conducted using a Fast Response Flame Ionization Detector (FFID) with Sampling Spark Plug (SSP) fits, then the in-cylinder equivalence ratio near the spark plug was estimated from the measured HC concentrations. In addition, the effects of the 1st injection timing, 2nd injection timing, and total equivalence ratio on the mixture formation near the spark plug were analyzed by means of experiments.

In the present work, a relative comparison of addition of water to diesel through emulsion and fumigation methods is explored for reducing oxides of nitrogen (NOx) and smoke emissions in a production small bore diesel engine. The ratio of water to diesel was kept the same in both the methods at a lower concentration of 3% by mass to avoid any adverse effects on the engine system components. The experiments were conducted at a rated engine speed of 1500 rpm under varying load conditions. For engine studies using emulsion fuels, kinetically stable water-in-diesel nanoemulsions were prepared with 3% water concentration by mass of the total sample. The emulsion fuels formulated using commercial surfactants were transparent in appearance. The droplet size of the nanoemulsions was characterized using dynamic light scattering technique.

Combustion concepts for future SI engines try to meet CO2 emission commitments and legislation all over the world. Where the diesel engine has an advantage by principle, the efficiency of the SI engine has to be improved significantly, while of course there must be no deterioration in exhaust emissions. Another approach is to switch from gasoline to gaseous fuels such as compressed natural gas (CNG) or liquefied petroleum gas (LPG) with more appropriate C/H ratios in order to reach the CO2 targets. Both methods of using liquid and gaseous fuels in an SI engine take into account that the air/fuel mixtures in the combustion chamber turn to a lean air/fuel ratio to increase engine efficiency, whether by stratification or air dilution. The challenge in this case is to solve the conflict between high efficiency and low raw emissions, especially in the field of NOx emission.