THE JOURNAL OF ENGINE RESEARCH
Year:2014 | Volume:10 | Issue:37|Papers Count:6

The purpose of this paper is troubleshooting, adjusting and analysis of a useful diesel engine fuel injector from common rail system with experimental and laboratory investigations. In the new diesel engines, the fuel common rail system has an important contribution to increase efficiency and improve engine performance. The injector as one of the most important and advanced components in the common rail system has numerous failures in test engine. For this purpose, different parts of a sample injector are introduced. Based on the results of 200 injectors and step back from the client to identify potential failure modes it is cleared that three sets of magnets, valve and needle are the weaknesses and vulnerable parts of an injector. To the experience of researchers in the most time, adjusting the Shim thickness of the injector is the easiest and most effective way to repair and reset of it. To achieve the optimal placement of shims in a test rig, various thicknesses of shims was placed in the injector.Penetration of the spray, spray cone, droplet size and performance of the motor in vehicle test were evaluated to achieve the optimal placement of the shims. The results show that in each case the parts to fix it, there is an optimum thickness Shim that it is certified in the both injector flow test and the actual engine test.

Hydrogen is a specified one among alternative fuels named for reducing carbon dioxide in exhaust gas. Hydrogen can be injected into runner or directly within the combustion chamber. However; direct injection would be desired because it would reduce the risk of preignition and backfiring besides recovering volumetric efficiency losses. Injection parameters play a significant role in direct injection engines. In this paper, a direct injection hydrogen fueled engine is simulated in AVL-Fire commercial software and the results are validated with experimental data from reference works. The effects of injection pressure, injector angle and spark plug position have been investigated. Results showed that increasing injection pressure would improve engine performance with increase in nitrogen oxide pollutant. Tilting the injector toward spark plug would make a rich zone near spark thus better combustion process. The study was continued focusing on spark plug position and selecting the best position due to charge stratification.

High thermal strength, low weight and capability of fast catalyst convertor warm up are main advantages of sheet metal exhaust manifolds which made it the best option for engines with maximum exhaust temperature more than 900 oC. A sheet metal exhaust manifold has been designed in this paper for EF7-TC engine which is four stroke bi-fuel CNG-gasoline engine. The proposed sheet metal exhaust manifold would be replaced with current Ni resist cast iron manifold. Design of exhaust manifold has been undertaken following the packaging constraints in the engine and required exhaust gas flow characteristics. Manufacturing process of design sheet metal exhaust manifold was simulated using AUTOFORM software. In finite element analysis effects of sheet thickness, its material and friction coefficient were investigated on sheet tearing. Results showed that AlSI321 can be used as a material for sheet metal with designed geometry. And drawing of sheet with these characteristics can lead to no defects on final formed sheet.

Due to extreme exploitation of fossil fuels and its consequence pollution, electrical hybrid cars are the most efficient mid-term solution to reduce issues instigated by environment pollution and the increase in fuel consumption. In this thesis, first, different kind of electrical hybrid cars and power transmission in this sort of cars are investigated. Then, an engine in hybrid and electrical car-based on former studies-considered and all fundamental criteria are compared. Subsequently, the car was molded in Advisor software and after validation of our model, with the regard of the superiority of parallel hybrid systems, a parallel hybrid system employed to study hybrid systems. After analyzing influential parameters on hybrid car performance, in order to gain the lowest fuel consumption as well as maintaining dynamic performance of the car, PSO algorithm used to optimize significant parameters. Eventually, the fuel consumption reduced by sixteen percent. It is also noted that in the case of urban electricity usage in first twelve kilometers a forty percent increase in efficiency can be achieved. In another case, where in addition to power system, transmission system was optimized a five more percent in reduction can be reach which sums up to twenty one percent reduction in fuel consumption.

Emissions from diesel engines, such as nitrogen oxides (NOx), carbon monoxide and particulate matter (PM) impose a major threat to the environment and human health. As for the reduction of NOx emission though, the widely used technique is to return a portion of the exhaust gases to the intake of the engine after cooling them in a heat exchanger known as exhaust gas recirculation (EGR) cooler.However, EGR coolers are prone to severe fouling dominantly due to deposition of particulate matter, i.e. soot on heat transfer surfaces that result in profound deterioration of thermal efficiency. In this study, deposition and removal mechanisms of particulate matter are investigated. Also a one-dimensional model is developed which predicts the behavior of particulate fouling in EGR coolers taking into account the underlying deposition and removal mechanisms and energy equations associated with the particle mass conservation. The theoretical results are then compared with those of experiments of which the agreement between them shows the validity of the proposed model.

In this work two main blocks of integrated circuit for knock signal detection has been modeled. The main goal of modeling key components of knock detection IC is to provide a software tool in order to reduce the number of experiments during calibration of knock parameters in ECU. In conventional method experimental data requires for calibration of knock related parameters for each central frequency of the filter and for several operating conditions of the engine. Since there are several parameters such as beginning and end of knock window phase, time constant of Integrator circuit, input signal gain and filter central frequency, the calibration task requires lots of measurements which is time consuming and expensive.Therefore we propose a behavioral model for two main blocks of knock signal detection integrated circuit, which enable us to use simulation instead of measurement for calibration purpose. A model of knock IC filter has been developed based of frequency response analysis, and then this model has been optimized using genetic algorithm. Similar technique has been used to model the integrator block of the IC. Comparing the model simulation results with experimental data under different engine speed and load and at several central frequencies demonstrates that the model has a reasonable accuracy with maximum error of 4.78%.