Hüseyin Serdar Yücesu

Effect of Cotton Seed Oil Methyl Ester on the Performance and Exhaust Emission of a Diesel Engine

Numerous studies indicated that oil sources in the world will come to an end. As a result, new alternative energy sources will be required to substitute for oil. Some of the experimental studies showed that vegetable oil can be used as alternative fuel in diesel engines. The viscosity of vegetable oil is much higher than that of standard diesel fuel; therefore, the high viscosity of the vegetable oil can cause problems for injection systems and engine components. To decrease viscosity, cottonseed methyl ester was obtained from raw cottonseed oil by transesterification method. In this study, cottonseed methyl ester was used in a four-stroke, single cylinder, and air-cooled diesel engine as alternative fuel. Engine tests carried out at full load-different speed range, the engine torque and power of cottonseed oil methyl ester was found to be lower than that of diesel fuel in the range of 3–9% and specific fuel consumption was higher than that of diesel fuel by approximately 8–10%. CO 2 , CO, and NO x emissions of cottonseed methyl ester were lower than that of diesel fuel.

Construction and testing of a dish/Stirling solar energy unit

AbstractThis study is concerned with the construction of a simple solar energy conversion system consisting of a parabolic dish concentrator and a Stirling engine. For this purpose, a parabolic dish concentrator consisting of planar mirror segments was built and coupled with a Stirling engine recently developed by the authors for solar energy conversion and domestic cogeneration. By mounting the engine to the bottom of the dish concentrator, the solar rays were directly reflected onto the hot end of the displacer cylinder. For the design of an appropriate parabolic dish concentrator reflecting solar rays onto the hot zone of a displacer cylinder and satisfying their uniform distribution, an equation was derived. The energy conversion unit constructed was tested under 820 W m−2 solar radiation. The engine started to run at 93°C hot end temperature. At steady running conditions, the hot end temperature of the displacer cylinder became stable at ∼156°C. The variation of shaft power with engine speed and char...

The Effects of λ and ∊ on Engine Performance and Exhaust Emissions Using Ethanol–unleaded Gasoline Blends in an SI Engine

Abstract In this study, the effect of relative air-fuel ratio (λ) and compression ratio (∊) on engine performance and exhaust emissions was experimentally investigated. The experiments were performed by varying ethanol–unleaded gasoline blends as E0 (100% unleaded gasoline), E10 (10% ethanol and 90% gasoline blend), E30 (30% ethanol and 70% gasoline blend), and E85 (85% ethanol and 15% gasoline blend). In experiments, first the effects of ethanol–unleaded gasoline blends on engine performance and exhaust emissions at 0.931, 1, and 1.069 λ values were clarified. Second, tests were carried out with compression ratios of 7:1, 9:1, and 11:1. The results indicated that the relative air-fuel ratio and ethanol content play an important role in reducing CO (carbon monoxide emissions) and HC (hydrocarbon) emissions. Results also showed that the engine power was slightly decreased, especially at higher engine speeds. A probable knocking phenomenon did not occur with the increase of compression ratio because of a higher octane number of ethanol–unleaded gasoline blends.