Sharif Digital Repository

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... 

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... 

Today, spark ignition internal combustion engines make up a large percentage of passenger car engines, so their performance improvement is important. Turbocharging of these engines, although is an appropriate method to enhance their specific power and improve their specific fuel consumption, but it has big problems such as the possibility of knock and increasing the NOx emissions in the engine. In this study, resolving these problems is intended by controlling the engine inlet charged air temperature to improve performance of the engine. For this purpose, the investigations are conducted experimentally as well as numerically. The experimental studies are carried out on a turbocharged... 

Knock is an abnormal phenomena in combustion engines and one the main limiter elements in increasing engine efficiency. From years ago, recognition and elimination of this phenomenon had studied by investigators and various approaches to anticipation had presented. One of the newest methods is using of property variety in air and fuel mixture with using technologies like Variable Valve Timing (VVT) system.
The purpose of this work is development a simple model in basis physics of 3 zone, homogeneous, ignition combustion with a partial kinetics model that this model can predict the knock phenomenon onset with good precision for various qualities of mixture. This study survey effect of... 

Ethanol is a promising alternative fuel in terms of addressing future energy and environmental problems, so we can use ethanol as a fuel in passenger cars to eliminate enviremental problems. in this study, the CEV13-038 injector from ACRUS company is modeled. the research purpose is focused on the effect of ethanol , geometrical parameters, and the fuel type on the injected mass quantity and on turning the fuel supply system from a gasoline based system to ethanol based one.
In the first step of this study, The effect of ethanol, fuel temperature, needle lift, nozzle diameter and number of nozzles... 

The purpose of this study is to determine a function which estimate fuel/air equivalence ratio distribution inside combustion chamber of spark ignition engine for pollution minimization and maximum efficiency. To do this, we developed a code by which, we are able to model one SI engine cycle.
Seven distributions for fuel/air equivalence ratio were examined which include: Homogeneous, linearly decreasing, linearly increasing, sinusoidal increasing and decreasing, sinusoidal decreasing and increasing, cosinusodal decreasing, and cosinusodal increasing. The average fuel/air equivalence ratio for all of these distributions was 0.85.
The results for indicated power showed that,... 

In this research energy and exergy Balance has been studied for a turbocharged three-cylinder engine. Energy balance is a method based on the first law of thermodynamics and based on this method the control volume is selected on the engine and the input and output energies of the control volume are calculated. Exergy balance is also a method based on the second law of thermodynamics which achieves the amount of irreversibility and ability to convert useful work for different energies in the control volume. In the tests performed, the net output power, output exhaust energy, energy transferred to the cooling fluid and other energies, including convection and radiation heat transfer from the... 

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... 

According to limitation of fossil fuel consumption and cost, reduction of fuel consumption is very important in internal combustion engine. This requirement becomes twofold in light of the greenhouse effect of CO2 on global warming. Therefore, the use of engines with less fuel consumption is a global success. Diesel engines are among the most productive internal combustion engines. They have a lower fuel economy and carbon monoxide. But unfortunately, these engines respectively in rich and dilute blend have highly soot and nitrogen oxides. One of the methods in the development of the combustion process is the low temperature combustion method, which reduces the production of Knox due to low... 

Combustion and NOx emissions were simulated by quasi-dimensional and ratereaction methods respectively in a turbocharged CNG engine. Mean-value turbulence modeling was carried out during compression and combustion processes to simulate combustion process better. The most appropriate NG flame speed for the CNG turbocharged engine was applied and ignition delay was ended when flame radius became more than turbulence integral length scale. Hemispherical flame propagated from spark gap center and its intersection with reciprocating Mexican-hat piston bowl was calculated analytically. Thermal boundary layer, as a novel approach, was considered in the simulation and a better agreement of predicted... 

At today’s crowded world, the importance of automobile transportation is obvious for all. The fossil fuel pollution crisis has increased the need for renewable-fueled engines with higher efficiency and lower emissions. Meanwhile, biofuels have received more attention for reasons such as carbon dioxide cycling, Affordability and availability. However, despite these benefits biofuels require crops such as corn or potatoes to produce, which in turn produce other environmental pollution. On the other hand, concerns have been raised as to whether the use of these fuels increases the amount of other pollutants, except for carbon dioxide, or not. Extensive researches in this field by experimental,...