Sharif Digital Repository

Electronic engine control unit (ECU) operates the different actuators using information signals received from the different sensors. Also in the case of any fault in the sensors and actuators operation ECU is responsible to detect and alert the accruing faults. Most of the common faults in the engine such as leakage in intake system and ignition system are not detectable by ECU, on the other hand ECU fault codes some times are hard to interpret or misleading. So fault diagnosis is usually based on experience of repair staff, and might be time consuming and inaccurate. In this study, using the knowledge of premixed fuel injection SI engines and emission generation and statistical data,... 

The Rotary Combustion Engines are known as Wankel Engines, for the first time designed and built by German inventor, Felix Wankel. In open letrecher, research reports about these engines are much less than piston engines. While, the wankel engine hase many advantages such as lower volume, less weight, less vibration and use of fuels lower octane number in compared with reciprocating engines. Therefore, it has particular importance in industries such as aircraft manufactueres.In this theses after the introduction chapter, Wankel engines and Turbochargers usage are reviewed. Then the Wankel engine and its turbocharging are searched in letrecher. Then, a computer code for simulation the Wankel... 

Nowadays, fuel optimum used in engines is an important matter. To achieve this aim, we need to tune engine. The big companies have paid attention to these cases. Because of it, there are strict standard in the world and in other side the internal combustion engine is very common.
In the internal combustion engine after cylinder, the gas inter to an encasement which is called exhaust manifold. In the other hand, exhaust manifold is in upstairs of turbine and waste-gate in turbocharged SI engines. To control fuel used and descries the amount of emissions, exhaust manifold pressure is very important. In the other hand, monitoring of exhaust manifold pressure can use for fault detection of... 

Nowadays internal combustion engines play an important role in the power generation as well as transportation fields all over the world. By using the turbocharger in internal combustion engine, more power is obtained in compare with aspirated engine having the same size, which is limited for gasoline engines. In this research, by a three-zone computer simulation code and experimental tests, the power boost limitations of the gasoline turbocharged engine are investigated. The results of single cylinder aspirated gasoline engine tests are used for validation the natural aspirated part of the code. For validating the turbocharged engine simulation, the results of a four cylinders gasoline... 

Proper operation of a spark ignition engine is required by comfort demands of a vehicle driver and governmental legislations. Therefore it is essential to monitor, within an online technique, the engine and detect any fault which disrupts its operation. The gas exchange path (including the intake and exhaust subsystems) is an important part of turbocharged engines responsible for accurate control of both engine power and emissions. Monitoring the path for fault detection and isolation (FDI) has been always demanded due to many failures it may face since the turbocharger exasperates the harsh working conditions for components involved in the path. This paper presents a novel model-based... 

Detecting of coherent structures in bidirectional vortex combustion chamber is the original aim of this project. For this aim a numerical simulation is performed by using OpenFOAM, open-source CFD software. Also influence of fuel nozzle places in formation of coherent structures is analyzed. Effects of combustion in these structures and differences in cold and hot flows are analyzed too. There are papers that present influence of coherent structures in vortex burners and other applications, but based on reviews that are performed in this work, it seems that influence of coherent structures have not seen in bidirectional vortex chambers. So it can be one of innovations of this work. Swirl... 

Numerical investigation of flow field and determination of velocity components in swirl flow are novel and important subjects in combustion chamber of swirl flow. The exact understanding of vortex phenomena and flow structures in vortex engine results in better design and control in terms of stability, geometry, cooling, and combustion efficiency. Although, numerical approaches are computationally complex, they are worthwhile and efficient. The aim of this work is to study the velocity field in a bidirectional swirl flow within the combustion chamber using numerical approaches. The investigation of flow field has been performed in the cold chamber. Four different models (RSM and LES) have... 

The aim of this research is value based optimum design of structures to minimize the costs imposing on them during lifetime. For this purpose, an optimization procedure is used to get optimum solutions. Therefore, in this optimization problem, total costs are objective functions and required limits of codes are as the constraints. The costs include initial costs of constructing and life cycle costs. The weight of structural components and seismic consequences during the lifetime of structure are used as a criterion to assess initial costs and life cycle costs, respectively. In this research, seismic losses are determined based on the probabilistic seismic assessment framework, which depends... 

The growing use of fossil fuels and their impacts on the environmental pollution, mostly originating from internal combustion engines, is one of the important issues in environmentally friendly energy management. One of the key solutions to improve engine performance and reduce exhaust emissions of internal combustion engines is direct injection of bio-fuels. In this regard, in the present study some new biofuels such as Bio-Norouzak, Modified Bio-Ethanol (MBE), and Modified Bio-Diesel (MBF) have been introduced and effects of different parameters on their sprays have been investigated experimentally and analytically. The literature survey shows there is not any comprehensive study on the... 

Today, the importance of transportation and motor vehicles is crystal clear for everyone. On the other hand, energy crisis and the emissions of these vehicles are two fundamental problems of internal combustion motors. On account of this, the diesel vehicles have absorbed researchers’ attentions due to their higher efficiency and low fuel consumption.Due to high diesel vehicle efficiency, it is tried to substitute gasoline vehicles with these vehicles. In addition, the unrecyclable nature of fossil fuels has led to more attention to renewable energies such as biofuels. A lot of kinds of herbal oils have identical characteristics with diesel fuel.In this research, the combustion of Rapeseed... 

The project aims to select the best Waste gate opening pressure for my Turbocharged gas engine is m355G. For this purpose GT-power software for modeling engine power is used. it is reduced to the 38/11 percent. After checking the model in several Waste gate opening pressure Turbocharged Gas engine performance is evaluated and the best Waste gate opening pressure is achieved. The results show that the engine brake specific fuel consumption by changing the opening pressure of 165 mm Hg to 255 mm Hg 4/03 percent and 14/19 percent of the engine power is increased. Also opening pressure of 265 mm Hg to 255 mm Hg engine brake specific fuel consumption 0/25 percent and 0/88 percent of the engine... 

Torque variations caused by intermittent combustion and inertia effects of reciprocating components, exert significant torsional excitation on crankshaft of internal combustion engines. These excitation induces considerable torsional vibration on crankshafts. Therefore, modeling and analysis of crankshaft torsional vibration and absorber systems, especially in automobiles engine that crankshaft tolerate high amplitude excitations coupled with heavy inertia effects has high importance. In this study, ability of centrifugal pendulum vibration absorber and dual mass flywheel which used in rotating machinery for vibration reduction, will be examined. At first, cranktrain will be torsionaly... 

Generally, the concept of producing ‘spare parts’ of the body for replacement of damaged or lost organs lies at the core of the varied biotechnological practices referred as tissue engineering. Tissue engineering is an interdisciplinary field that incorporates principles of engineering with the life sciences. Tissue engineering is based on three principle; cells, scaffolds for cells expansion, attachment as an environment like ECM and growth factors. These things together can help tissue engineers to provide microenvironments which are suitable for special cells. The most important thing in this kind of works is the ability to simulate environment for cells the same as body. According to the... 

Project is defined as all activities with a definite beginning (start) and end (finish) aiming to achieve a defined target through defined resources. Literature reviews in the field of project management have shown the importance of project management capabilities for evaluation and optimization. There are many factors in project management which can lonely disrupt the timing and progress of the project. One of the most important factors that in effective and unfortunately has been less measured due to its intangible characteristic in the project is known to be the "human factor". This factor is involved from the first day a project starts and will continue till the end of the project.... 

With the increasing complexity of manufacturing processes and the interrelations between the different phases, the possibility of a phase being affected by a preselected desing variable is very high. In that case, the influence of a desing variable not only on the part performance of but also on the feasibility and efficiency of its manufacturing should be considered. Concurrent engineering approaches should then be adopted to take the control of such complicated relations among the subprocesses. In this thesis a concurrent design optimization methodology was proposed to minimize the cost of a cold forged manufacturing process using the design parameters as optimization variables. An... 

The emergence of various software development processes with different aspects raises the need to evaluate and measure their capabilities and deficiencies. The evaluation must consider different parameters of software development projects and their similarities, differences and features in the context of existing methodologies; therefore we need criteria that cover these needs. Apart from the research that has been done on analysis and evaluation of software development methodologies and processes, there is a need for a general multi-aspect framework for the evaluation of methodologies with different aspects. Lack of general criteria for covering different aspects and the inadequacy of... 

Most motorcycles in developing countries use carburetor systems as the fuel delivery method especially for models with the cubic capacity of less than 150 cc. However, a small gasoline fuelled engines operating using carburetor system suffer from low operating efficiency, waste of fuel and produce a higher level of hazardous emissions to the environment. A retrofit fuel injection system (FIS) is a system that is developed to entirely replace the conventional carburetor system to improve its fuel economy and exhaust emissions providing a low-cost alternative in an effort to reduce fuel costs and air pollution. In this study, an electronic control unit (ECU) is designed for a fuel injection... 

Manage time, cost and quality, project managers are a major concern for the violation of any of the causes to bring costs and fines will be detrimental. Collect all the main factors contributing to delays in construction projects to three main factors employer, contractor and external factors reached. An algorithm is presented in this study are presented in addition to the reasons and factors affecting the delay of engineering documents, the contribution of each factor in the delay of the project will help the project. Implementation algorithm In the Pargas farayand Company of Pakaging projects sulfur solidification  

In the present study, a heat recovery system for a distributed generation plant (DG) with a 1 MW gas combustion engine has been designed. The purpose of this designing is converting the power plant to a CHP system. For the existing heat recovery system, a shell & tube heat exchanger is designed to recover the thermal energy from exhaust gases and a plate heat exchanger is designed to recover the thermal energy from the engine jacket cooling fluid. The heat exchanger design has been calculated manually and also by use of software. In the software calculation, the heat exchanger design has been done by use of the Aspen HTFS +2006.5 software. In the manual one, the Kern equation (1950) was... 

Developing ESP knowledge of a specific academic discipline is not only a privilege but a prerequisite for successful performance in related academic and occupational settings. English for Specific Purposes (ESP) courses at undergraduate level in Iranian universities are designed to serve this purpose. Needs analysis is the foremost step to design relevant and useful ESP courses, but how to approach needs in a motivating and interesting way is still a question pending further research. Accordingly, focusing on engineering fields in three Iranian state universities, this study aimed at identifying factors that affect engineering students’ motivation for learning technical English in ESP...