Automotive Science and Engineering
Year:2012 | Volume:2 | Issue:3|Papers Count:7

The current regulated particle metric in vehicle emissions is the total mass, while during last decade; interest in number size distribution has increased. Various international studies on epidemiology and toxicology have reported the adverse effect of the particle matter on public health. The UNECE group of experts on pollution and energy (GRPE) under particle measurement program (PMP) are under the process of finalization long term certification standard concerning particle emissions. The current study was done in order to investigate the number concentration from a range of Indian multi utility vehicles. These were equipped with various sizes of diesel engine over the new European driving cycle (NEDC) cycle using same oil specification. The vehicles chosen were meeting emission norms ranging from Euro3 (E-3) to Euro5 (E-5) and using the corresponding fuel specification as specified for the norms. In order to meet the strict emission norms, penetration of common rail injection system in the Indian market is inevitable. The use of higher injection pressure, advanced after treatment systems such as diesel particle filters (DPF), is the motivation for the work to access the number concentration, an important metric of particle matter in view of future emission norms. It is clearly revealed that different vehicles equipped with different capacity engines exhibits similar diesel particle emission characteristics. Also, as the particle mass is decreasing with the stringent emission norms reduces the particle number concentration.

In this study it has been tried, to compare results and convergence rate of sensitivity analysis and conjugate gradient algorithms to reduce fuel consumption and increasing engine performance by optimizing the timing of opening and closing valves in XU7/L3 engine. In this study, considering the strength and accuracy of simulation GT-POWER software in researches on the internal combustion engine, this software has been used. In this paper initially all components of engine have been modeled in GT-POWER. Then considering the experimental result, results confirmed the accuracy of the model. After model verification, GT-POWER model with MATLAB-SIMULINK are coupled each other, to control the inputs and the outputs by sensitivity analysis and conjugate gradient algorithms. Then the results compared with experimental results of initial engine too. The results indicated that optimal valve timing significantly reduced brake specific fuel consumption and when is used variable valve system for opening and closing angle of intake and exhaust valves, the mean improvement percentage in brake specific fuel consumption from sensitivity analysis is nearly 5.87 and from conjugate gradient is about 6.69. too, for example with increasing engine speed late closing intake valve causes optimized brake specific fuel consumption and from 3500rpm this trend stops and in 4000rpm and 4500rpm early closing of intake valve results in more optimized brake specific fuel consumption. Then up to 6000rpm again late closing of valve would be favorable. Also results indicated that convergence rate of conjugate gradient algorithm to reaching the optimal point is more than sensitivity analysis algorithm.

Global air pollution is a serious threat caused by excessive use of fossil fuels for transportation. Despite the fact that diesel fuel is a big environmental pollutant as it contains different hydrocarbons, sulphur and crude oil residues, it is yet regarded as a highly critical fuel due to its wide applications. Nowadays, biodiesel as a renewable additive is blended with diesel fuel to achieve numerous advantages such as lowering CO2, and CO emissions as well as higher lubricity. However, a few key drawbacks including higher production cost, deteriorated performance and likelihood to increase nitrogen oxide emissions have also been attributed to the application of diesel-biodiesel blends. Expanded polystyrene (EPS), known as a polymer for packaging and insulation, is an ideal material for energy recovery as it holds high energy value (1 kg of EPS is equivalent to 1.3 liters of liquid fuel). In this study, biodiesel was applied as a solvent of expanded polystyrene (EPS) during a special chemical and physical treatment. Various percentages of EPS in biodiesel blended diesel were tested to evaluate the fuel properties, emissions and performance of CI engine. The results of the variance analysis revealed that the addition of the additive improved diesel fuel properties by increasing the flash point as well as the reduction of density and viscosity. Despite a 3.6% reduction in brake power, a significant decrease in brake specific fuel consumption (7.26%) and an increase in brake thermal efficiency (7.83%) were observed at the full load and maximum speed of the engine.Additionally, considerable reductions of CO, CO2, NOx and smoke were achieved.

This thesis looked at the effect of clay and silt soil blocking the heat transfer area of the radiator and its effect on the engine coolant through the conduct of experiments and a mathematical model developed. The results indicated that the percentage area covered resulted in a proportional increase of the inlet and outlet temperatures of the coolant in the radiator. The mathematically model developed also predicted the experimental data very well. Regression analysis pointed out that every 10% increase area of the radiator covered with silt soil resulted in an increase of about 17 oC of the outlet temperature of the radiator coolant.Similarly, using clay as a cover material, 10% of the area covered of the radiator resulted in an increase of about 20 oC of the outlet temperature of the radiator coolant. Statistical analysis pointed to the fact that the result obtained for clay, silt and the mathematical model were not significantly different. Thus, irrespective of the type of material that blocks the radiator surface area, the coolant rises with proportion of the radiator covered.

In this paper, finite element elastic contact analysis of a functionally graded (FG) hollow brake disk in contact with pad, subjected to rotation, contact pressure and frictional heat is presented. The material properties vary through the thickness according to a power-law characterised by a grading index, n. The material property is purely steel at the core part and gradually moves and approaches to the ceramic properties at the surfaces of the FGM disk. In this task, thermal analyses are performed on two ventilated disk brake one of them is constructed of functionally graded composite material and the other is a homogeny disk brake which is constructed of steel alloy. In this study three-dimensional finite element model and ABAQUS software is used. Through comparison of temperature and displacement fields the benefits of using functionally graded material is investigated. It is shown that temperature variation in FGM disk is much lower than steel disks, it may be concluded that FGMs disk restrain the growth of thermal perturbation and delay the contact separation.

During the design and development of truck cabins, the safety of the driver and the front seat passenger in an accident is an important task and should be considered. The cab must be designed in such a way that in an accident a sufficient survival space is guaranteed. The aim of this study is to investigate the behavior of Iran Khodro (IKCO) 2624 truck subjected to a complex crash test according to regulation ECE-R29. This regulation is a comprehensive European regulation consisting of three tests: 1-Front impact test (Test A), 2-Roof strength test (Test B), 3-Rear wall strength test (Test C). These tests do not consider the safety of the occupant directly; however, a III-50th% dummy was used to assess the cab’s deformations relative to the driver survival space. A 3D finite element model of the cab and chassis was developed and subjected to tests by using LS-DYNA software. The results indicate that the cab complied with Test A and C successfully while it passed Test B marginally. Finally, two solutions are suggested and implemented to improve the cab’s response for Test B.

In order to reduce both the weight of vehicles and the damage of occupants in a crash event simultaneously, it is necessary to perform a multi-objective optimization of the automotive energy absorbing components. In this paper, axial impact crushing behavior of the aluminum foam-filled thin-walled tubes are studied by the finite element method using commercial software ABAQUS. Comparison of the present simulation results with the results of the experiments reported in the previous works indicated the validity of the numerical analyses. A meta-model based on the feed-forward artificial neural networks are then obtained for modeling of both the absorbed energy (E) and the peak crushing force (Fmax) with respect to design variables using those data obtained from the finite element modeling. Using such obtained neural network models, a modified multi-objective GA is used for the Pareto-based optimization of the aluminum foam-filled thin walled tubes considering three conflicting objectives such as energy absorption, weight of structure, and peak crushing force.