Sharif Digital Repository

Thermodynamic analysis of a system is a method for recognizing the type of energy transmission between system and surrounding environment. It also helps to find how macroscopic properties of the system change during this process. This analysis is based on first and second laws of thermodynamic. The first law expresses conservation of energy and inspects quantity of energy transmission but doesn’t evaluate quality of energy. The second law expresses quality of energy and the ability of doing work. The analysis that uses both of the laws is named exergy analysis. By exergy analysis the place of useful energy losses in the system can be determined. In this research the exergy analysis of... 

Diesel engines have widely used in past hundred years. During this time costly and extensive researches have been done to improve engine performance, which is going on. Important issues of these engines are higher specific power and efficiency and lower specific fuel consumption and pollutions formation. One of the best methods for engine performance improvement is matching a convenient turbocharger on engine. A turbocharger increases the engine air mass flow rate by increasing the inlet pressure and density. Due to increase of fresh air mass flow rate, fuel mass flow rate and power would increase. The aim of this research is to choose the convenient turbocharger for the OM355 naturally... 

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... 

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... 

Duo to the strictly pollution legislation in the last decade and increasing demand of lightweight internal combustion engines with rated power , turbocharging of the spark ignition engines become more interested. Therefore the turbocharging of M15GS engine was studied in both gasoline and natural gas fuels with purpose of enhancement of performance characteristic of engine. According to this approach 0-D turbocharger matching performed for gasoline and natural gas fueled M15GS engine. Also an innovative 1-D turbocharger matching performed for gasoline fueled engine. Then engine equipped with SJ50 turbocharger and dynamometer and combustion development tests performed on gasoline fueled... 

Since the construction of the first models of internal combustion engines in the nineteenth century, efficiency and, since the late twentieth century, pollution and fuel consumption has been the main issue for researchers and manufacturers who have always sought to improve it. Manufacturers of internal combustion engines are required to perform numerous tests to carefully study and increase the level of technology and reliability of their products. There have been two ways for them to do this; the first way is to use the experimental method; that is, making multiple samples that require a high cost that makes it impossible. The second way is to use engine simulation software, which can be...