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This paper presents the principle and method of calculation for the coupled torsional-axial vibration of crankshaft for a high speed diesel engine based on Rayleigh differential method. At first, the internal combustion engine crankshaft was simplified to a continuous stepped shaft model and the kinetic formulas of shafts and masses were constructed. By means of the Lagrange formulation, the motion equation of torsional vibration and axial vibration were deduced. According to coupled principle and excited force of shafting system, a model of coupled torsional-axial forced vibration can be constructed. Applying a vector matrix, a single order or a whole system vibration can be analyzed. With a newly designed testing device, the axial and torsional vibrations of the crankshaft at the free-end of a 4-cylinder diesel engine were measured. Compared with the practical measurement results, the calculated results are to be in agreement in main order.

Now-a-days, customers are turning more sensitive towards vehicle NVH performance. In order to enhance customer NVH comfort, a specific noise phenomenon was investigated during product development. While testing stop-go traffic conditions, cyclic noise was observed in the 1st gear with the vehicle creeping. The noise was similar to a gear rattling noise. It was perceived unpleasant due to low background noise and wide frequency range of cyclic noise. This paper explains the root cause of this cyclic noise through various drivetrain experiments and also elaborates the experimental analysis approach in order to arrive to the solution in gear and clutch design for cyclic noise elimination.

Due to the mechanical forces under static conditions, the engine cylinders cross section will not be a round circle any more once they are installed. The deformation of an engine cylinder causes increasing lubricating oil consumption and abnormal wear, resulting in worse fuel economy and emissions. However, prediction of deformation on a liner has not been made because of the complication of conditions and structure. In this study, a V6-type engine body model was built and meshed with Hypermesh suit software. Then, cylinder deformation under static condition has been simulated and analyzed. First of all, experimental work was done to verify the engine model. Basically, few parameters like pre-tightened force, structure and distribution of bolts have been investigated to figure out how the cylinder bore deformation behaves via finite element analysis. Also, a simple Matlab program was developed to process the data.

Increasing advancement in automotive technologies ensures that many more lightweight metals become added to the automotive components for the purpose of light weighting and passenger safety. The accidents are unexpected incidents most drivers cannot be avoided that trouble situation. Crash studies are among the most essential methods for enhancing automobile safety features. Crash simulations are attempting to replicate the circumstances of the initial crash. Frontal crashes are responsible for occupant injuries and fatalities 42% of accidents occur on frontal crash. This paper aims at studying the frontal collision of a passenger car frame for frontal crashes based on numerical simulation of a 35 MPH. The structure has been designed to replicate a frontal collision into some kind of inflexible shield at a speed of 15.6 m/s (56 km/h). The vehicle’s exterior body is designed by CATIA V5 R20 along with two material properties to our design.

An HSDI Diesel engine was fuelled with standard Swedish environmental class 1 Diesel fuel (MK1), Soy methyl ester (B100) and n-heptane (PRF0) to study the effects of both operating conditions and fuel properties on engine performance, resulting emissions and spray characteristics. All experiments were based on single injection diesel combustion. A load sweep was carried out between 2 and 10 bar IMEPg. For B100, a loss in combustion efficiency as well as ITE was observed at low load conditions. Observed differences in exhaust emissions were related to differences in mixing properties and spray characteristics. For B100, the emission results differed strongest at low load conditions but converged to MK1-like results with increasing load and increasing intake pressures. For these cases, spray geometry calculations indicated a longer spray tip penetration length. For low-density fuels (PRF0) the spray spreading angle was higher.

Vehicle launch shudder is the terminology used in automotive industry to describe severe longitudinal oscillation during clutch engagement under start-up condition. This paper presents and implements detailed investigation for dry-clutch engagement and disengagement process, in order to deeply analyze vehicle launch shudder phenomenon which seriously deteriorates ride comfort. Firstly, diaphragm spring and cushion spring and link strip, which are three elastic components related to dry-clutch engagement and disengagement process in axial direction, are studied for their elastic properties, respectively, to obtain relationship between load and deflection. The elastic properties of these three elastic components are taken into considerations to establish nonlinear relationship between release bearing travel and clutch clamp force.

Strict emission regulations and the need of higher efficiency of future dual fuel engines require an optimized combustion process. For getting a better understanding of the in-cylinder combustion process optical investigations represent a powerful tool. For medium speed dual fuel engines, optical investigations are pretty rare respectively not available. Especially the avoiding of knock events within the combustion process is a key development topic to realize high engine load and high engine efficiency. For the investigations a fully flexible dual fuel test engine was used. The engine is operated with a natural gas / air cylinder charge which is ignited by a small micro pilot diesel injection within the gas mode.

Metal matrix composite processing allows the possibility of improving both mechanical and damping properties by selecting reinforcements which have high damping characteristics, hardness and strength. In this work, the effect of disperse SiC as passive agents on the dynamic properties such as damping ratio, loss factor and effect of damping factor on Al7075/Al2O3/SiC composite machinability was studied. The composite samples were fabricated as Al7075/5%Al2O3, Al7075/5%Al2O3/5%SiC, Al7075/5%Al2O3/10%SiC and Al7075/5%Al2O3/15%SiC as well subsequently experimented. The dynamic properties were found using free vibration test approach and the hysteresis loop method. Further, the machinability in end milling operation was accessed by experimentation with the surface finish as the parameter under scrutiny. The composite Al7075/5%Al2O3/5%SiC has better damping ratio comparing to others, also the composite with the best damping capacity produces a fine surface finish during machining.

Hot forming process of ultrahigh strength boron steel 22MnB5 is widely applied in vehicle industry. It is one of the most effective approaches for vehicle light weighting. Dynamic recovery is the major softening mechanism of the boron steel under austenite state at elevated temperatures. Deformation mechanism of the boron steel can be revealed by investigation on the behavior of dynamic recovery, which could also improve the accuracy of forming simulations for hot stamping. Uniaxial tensile experiments of the boron steel are carried out on the thermo-mechanical simulator Gleeble3800 at elevated temperatures. The true stress-strain curves and the relations between the work hardening rate and flow stress are obtained in different deformation conditions. The work hardening rate decreases linearly with increasing the flow stress.

Contemporary high speed diesel engines require a compromise regarding the size of fuel nozzle orifices which should be small enough to assure a good fuel atomization at low engine speed, and large enough to provide the engine with high fuel dose at maximum power. Calculations were made to predict the dynamic response of a closed diesel injector within its unstable operation range. The pressure in the seat chamber under the needle was established as the key factor to simulate the injector's behaviour. It was measured at different flow conditions and used in calculations. After applying an optimization method, it was possible to predict how the design parameters of an injector should be changed in order to obtain the best dimentional configuration which improves the fuel atomization at low engine speed.

Compression ignition engines provide superior thermal efficiency over other internal combustion engines. Unfortunately the combustion process is diffusive combustion, meaning a lot of fuel is impinged the on the piston and cylinder wall. This creates cooling loss coupled with smoke, CO and THC. Minimization of the nozzle orifice diameter is a simple method widely used to shorten spray penetration. However, decreasing the nozzle orifice diameter also decreases fuel flow rate resulting in a prolonged injection and combustion process and reducing thermal efficiency. An offset orifice nozzle causes less fuel impingement by shorter fuel spray penetration without significant reduction of fuel flow rate. The offset orifice nozzle was made by shifting its alignment from the center of the sac to the edge of the sac following the swirl direction. A counterbore design was applied to maintain constant orifice length.

Waste utilization is found to be a challenging task all around the globe. Converting the waste into useful forms of energy is a significant landmark in meeting the demand of world energy requirement. Thus an attempt was made in this study to make use of Waste Cooking Oil (WCO) as a fuel to operate compression ignition engine effectively as it degrades both the environment and human health.WCO was collected form the hostel mess of the author institution. In the first phase of the study, a single cylinder water cooled diesel engine was developed and operated in a single fuel mode with neat diesel and WCO as fuel under various load condition. Engine was modified in the second phase of the work to operate in dual fuel mode with a low reactive fuel like ethanol as primary fuel. In this work ethanol was injected in the intake manifold using newly developed Electronic Primary Fuel Injection System (EPFIS).

In order to optimize the inner flow of the regenerative pump used in gasoline injection systems, we carry out experimental and numerical flow investigations. A qualitative analysis of spatial flow phenomena in selected regions of the pump is presented by employing the laser light sheet technique. Therefore, a tenfold enlarged water model is built up, where dynamic similarity with the original flow is achieved. The results of the flow analysis have led to improved geometries which are compared with the original design by measured pump characteristic curves. Furthermore, three-dimensional simulations of the fully developed turbulent flow using a finite-element method are presented. The flow with respect to the rotating impeller is calculated by solving the Reynolds equations in connection with the k-ε-turbulence model.

TWBs (tailored welded blanks) technology can open new avenues for obtaining components in the automotive, aerospace and electronics industries. Friction stir process (FSP) can control the properties by deep localized plastic deformation using the non-consumable tool. In this study, the primary objective is to investigate the effects of Graphene nanoparticles (GNPs) in AA7075 material and the effect of FSP graphene NPs on the forming limit curve of the TWBs through experiments. The micrographs of the weldment are obtained by metallography practices. Tensile specimens are separated for evaluating FSP weld zones. Obtained results exhibits the formability limit of AA7075 thin sheets and decrease FSP thin sheets formability as compared with the formability of base metals

In order to improve the performance and fuel economy of a reciprocating engine, it is important to reduce the overall engine frictional losses. In this paper, author conducts an experimental study on the friction characteristics due to pumping loss, valve-train system, piston assembly, auxiliaries and transmission for a 110cc, single cylinder 4-stroke gasoline engine using frictional strip-down analysis. Friction strip-down method is commonly used to investigate the frictional contribution of various engine elements at high speeds and for better understanding of the make-up of the total engine friction. The engine friction measurements for the particular engine are carried out on a motoring test rig at different engine speeds. In addition, the effect of engine operating parameters such as oil temperature and oil quantity in engine sump is also presented in detail.

Lubrication systems play a major role not only in the durability of modern IC engines but also in performance and emissions. The design of the lubrication system influences the brake thermal efficiency of the engine. Also, efficient lubrication reduces the engine's CO2 emissions significantly. Thus, it is critical for an IC engine to have a well-designed lubrication system that performs efficiently at all engine operating conditions. The conventional lubrication system has a fixed-displacement oil pump that can cater to a particular speed range. However, a fully variable displacement oil pump can cater to a wide range of speeds, thereby enhancing the engine fuel efficiency as the oil flow rates can be controlled precisely based on the engine speed and load conditions. This paper primarily discusses the optimization of a lubrication system with a Variable Displacement Oil Pump (VDOP) and a map-controlled Piston Cooling Jet (PCJ) for a passenger car diesel engine.

The high frequency of fatal head injuries of elderly people in traffic accidents is one of the important issues in Japan. One of the causes may be vulnerability of the aged brain. While a human head/brain FE model is a useful tool to investigate head injury mechanism, there has not been a research result using a model considering the structural and qualitative changes of the brain by aging. The objective of this study was to clarify the generational difference of intracranial responses related to traumatic brain injuries (TBI) under impact loading. In this study, the human head/brain FE models in their twenties (20s) and seventies (70s) were used. They were developed by reflecting the age-specific characteristics, such as shape/size and stiffness of brain matter and blood vessels, to the baseline model developed by Global Human Body Models Consortium (GHBMC) LLC.

The performance standards of Li-ion batteries used in EVs have skyrocketed, owing to their rapid commercialization in recent years. This has made Li-ion battery thermal management more vital than ever before, as optimum performance is achieved only when the batteries are within the narrow temperature range of 25° to 40°C. However, the operating temperatures in a lot of EVs go way beyond 40°C, leading to a reduction in the battery performance and lifetime. This study aims to solve this problem by improving the battery packing and maintaining the battery temperature via a hybrid cooling system which involves both air-cooling and liquid cooling. The aim is achieved by varying the liquid coolant used in the system and the cell arrangement in the battery module which has 32 cells in an 8x4 arrangement.

The paper describes a new disc brake design procedure including the ADAMS model of the air-operated brake disc mechanism and its validation against the conventional hardware. A mechanical system simulation is used in the paper to forecast the full dynamic behavior of the complex brake unit system having a lot of cooperating with each other parts.

The ignition of lubricating oil droplet has been proved to be the main factor for pre-ignition and the following super-knock in turbocharged gasoline direct injection engine. In this paper, the ignition process of lubricating oil droplet in combustible ambient gaseous mixture was investigated in a rapid compression machine (RCM). The pre-ignition induction by oil droplet of the ambient gaseous mixture was analyzed under different initial droplet volume and effective temperature conditions. The oil droplet was suspended on a tungsten fiber in the combustion chamber and the ignition process was recorded by a high-speed camera through the quartz window mounted at the end of the combustion chamber. The pressure traces were also obtained by a sensor in order to get the ignition delay and analyze the combustion process in detail.