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One of the most important environmental problems in the world is the increasing of greenhouse gas emissions. The biggest part of greenhouse gas emissions is caused by energy sector in the word. Additionally, transportation in the energy sector is the essential source of the man made emission of greenhouse gasses. Because of the rising of population and the development of technology, the emission of greenhouse gases has been rising. It's very important to invest in new technologies along with the enforcements of new regulations.In this study, the regulations about the end of life vehicles (ELV), applied in Turkey in 2003, was assessed as a model and the same model was applied in 2010 to predict the effect on greenhouse gas emission. Vehicles over 20 years have been accepted as ELV. Greenhouse gas emissions were calculated for two situations; ELV regulation is prevailed or not. In case of applying the ELV regulation, two approaches were accepted; (1) 30% of vehicles over 20 years will be disposed off, (2) a new car will be in traffic for each ELV which disposed off. The decrease of greenhouse emissions in 2010 and 2011 were examined as 0.3 % and 1.9 % for CO2; 1.2 % and 3.8 % for N2O; 3.9 % and 12.8 % for CH4; 5.3 % and 17.6 % for CO; 3.6 % and 12.4 % for NOx; 5.6 % and 18.4 % for HC, respectively. 50 % of road transport is consisted of cars. If all the vehicles were evaluated within ELV regulation, the decrease of greenhouse emission might be 2 times more. [ABSTRACT FROM AUTHOR]

Wind tunnel tests are used to determine aerodynamic characteristics of road vehicles. Between model and prototype to match Reynolds number its necessary to use high speed wind tunnel or larger models. This is an important factor that increasing costs. Reynolds number independence can be used to determine aerodynamic characteristics with low speed wind tunnel and smaller models. In this study 1/24 scale three car's drag coefficient were trying to determine with utilizing the Reynolds number independence. Tests were carried out in a wind tunnel which free flow velocity is 28 m/s. As a result of the tests, it has been seen that the Reynolds number independence can not be used for all models. According to test results, the drag coefficients of BMW X5 E53, Alfa Romeo 156 and Wolksvagen New Beetle were found with 14 %, 12.5 %, 7.8 % error, respectively. [ABSTRACT FROM AUTHOR]

This study investigates the experimental performance of an automotive air conditioning (AAC) system using an orifice tube as an expansion device for fixed and variable capacity compressors (FCC and VCC). An experimental AAC system using R134a as refrigerant has been set up in the laboratory, and instrumented. The system has been operated with FCC and VCC, and tested by varying the compressor speed as well as the temperatures of the air streams entering the condenser and evaporator. By applying energy analysis to the experimental system, its performance parameters have been evaluated for both compressor cases, and presented in comparative graphics. The experimental results show that the cooling capacity and the exergy destruction in the system usually increase with the compressor speed, while the coefficient of performance (COP) decreases with it. The cooling capacity and COP get higher on increasing the temperature of the air stream entering the evaporator or decreasing the temperature of the air stream entering the condenser. it is revealed that using the FCC yields 5-10% higher cooling capacity compared to the case of using the VCC, and causes higher COP values at low speeds. However, as a result of the intervention of the capacity control system, using the VCC yields higher COP values at high speeds. [ABSTRACT FROM AUTHOR]