Yakup İçingür

Effect of fuel cetane number and injection pressure on a DI Diesel engine performance and emissions

In this experimental study, the effects of different fuel cetane numbers (CNs) and fuel injection pressures on a Diesel engine emission and on the performance were investigated. For this purpose, the fuels with 46, 51, 54.5 and 61.5 CN were tested in a four cycle, four cylinder DI Diesel engine. Measurements were conducted for each of the injection pressures 100, 150, 200 and 250 bar. Keeping 150 bar injection pressure and the other parameters constant, the changes of engine performance for the different CNs were also tested at full load condition. The results showed that NOx, SO2 and CO emissions are reduced about 15% and 5%, respectively, when the fuel CN is increased for the standard injection pressure, but the smoke value is increased dramatically when the injection pressure is reduced to 100 bar. In contrast with the lower pressure, NOx is increased and smoke is decreased when the injection pressure is increased to 250 bar. Increases in engine torque by 5% and power output by 4% were observed at the maximum torque speed of 2500 min−1 when the CN is increased from 46 to 54.5. However, when increasing CN above 54.5, no significant increases in engine performance were observed.

A Comparison of Engine Performance and the Emission of Fusel Oil and Gasoline Mixtures at Different Ignition Timings

Alcohols have been used as a fuel for engines since 19th century. Among the various alcohols, ethanol is known as the most suited renewable, bio-based and ecofriendly fuel for spark-ignition (SI) engines. In addition, ethanol has higher evaporation heat, octane number, and flammability temperature therefore it has positive influence on engine performance and reduces exhaust emissions. In this study, engine performance and emission levels of unleaded gasoline and unleaded gasoline-fusel oil blends in a spark ignition engine, under variable ignition timings are investigated. Engine torque increased and brake specific fuel consumption (bsfc) decreased with the ignition timings. For F0 and F10 blends, hydrocarbon emissions changed by 22% on average and carbon monoxide (CO) emissions changed by 9.2%. It was also observed that nitrogen oxide (NOx) emissions were reduced.

Effect of comprex supercharging on diesel emissions

Diesel engine emissions are highly complex mixtures. They consist of a wide range of organic and inorganic compounds distributed among the gaseous and particulate phases. Particulates and NOx emissions are the important components of the Diesel exhaust. The composition of Diesel exhaust varies considerably, depending on engine type, operating conditions, fuel, and lubricating oil. In this research, the effects of supercharging, which is one of the engine operational parameters, on Diesel emissions have been investigated. For this purpose, a comprex, CX (pressure wave supercharger) was designed and manufactured and then matched to an indirect injection Diesel engine. During the engine tests, the emission parameters (CO, SOx, NOx and smoke density) have been observed and measured for different pulley ratios at full load conditions. The results showed that CX supercharging may be an alternative way of NOx reduction with some modifications.

FUZEL YAĞI BENZİN KARIŞIMLARININ BUJİ İLE ATEŞLEMELİ BİR MOTORDA PERFORMANS VE EMİSYONLARA ETKİSİ

Artan enerji ihtiyaci ve cevre kirliligi nedeniyle, buji ile ateslemeli motorlarda etanol, metanol, dogal gaz,hidrojen ve LPG gibi alternatif yakitlar kullanilmaktadir. Biyokutle kaynaklarindan uretilen alkoller yuksekoktan sayilari nedeniyle alternatif yakinlar icinde onemli bir yere sahiptir. Bu calismada kursunsuz benzin vefuzel yagi karisimlarinin buji ile ateslemeli bir motorda motor performansina ve egzoz emisyonlarina etkilerideneysel olarak incelenmistir. Deneyler dort zamanli, tek silindirli, enjeksiyonlu ve buji ile ateslemeli motordatam yuk sartlarinda gerceklestirilmistir. Degisik motor hizlarinda ve maksimum motor momentini veren ateslemezamaninda yapilan deneylerde, fuzel yagi ilavesi ile motor momentinde artis olmus ve en yuksek artis F30 yakitiile %3,4 olarak elde edilmistir. Butun motor hizlarinda ozgul yakit tuketimi, karisimdaki fuzel yagi miktarinabagli olarak artis gostermistir. En yuksek artis F30 yakiti ile %7,7 olarak elde edilmistir. Azot oksit (NOx)emisyonlari karisimlardaki fuzel yagi miktarina bagli olarak azalirken, hidrokarbon (HC) ve karbon monoksit(CO) emisyonlari artis gostermistir.

DÜŞÜK HIZLI BİR RÜZGAR TÜNELİNDE DEĞİŞİK OTOMOBİL MODELLERİNİN AERODİNAMİK DİRENÇ KATSAYILARININ BELİRLENMESİ

Tasit aerodinamik karakteristiklerinin belirlenmesi icin ruzgar tuneli testlerinden yararlanilmaktadir. Model veprototip arasinda Reynolds sayisi esligi saglanabilmesi icin ya cok yuksek hizli ruzgar tuneli kullanilmasi ya dadaha buyuk model kullanilmasi gerekmektedir. Bu maliyeti arttiran onemli bir faktordur. Daha kucuk olcekli vedaha dusuk ruzgar hizlarinda aerodinamik karakteristiklerin belirlenebilmesi icin Reynolds sayisibagimsizligindan faydalanilabilir. Bu calismada Reynolds sayisi bagimsizligindan faydalanilarak 1/24 olcekli ucotomobilin aerodinamik direnc katsayisi belirlenmeye calisilmistir. Testler maksimum serbest akis hizi 28 m/solan bir ruzgar tuneli ile gerceklestirilmistir. Test sonucunda butun modeller icin Reynolds sayisibagimsizligindan yararlanilamayacagi gorulmustur. BMW X5 E53, Alfa Romeo 156 ve Wolksvagen New Beetleotomobilleri ile yapilan testler sonucu aerodinamik direnc katsayilari sirasiyla % 14, % 12,5 ve % 7,8 hata oraniile bulunmustur.