The two-stroke engine has many advantages, including low maintenance costs, a high specific power, and a simple structure, compared to four-stroke engines. Since two-stroke engines use a fuel–oil mixture instead of fuel alone, two-stroke engines do not need an oil pan. Unlike the lubrication system in four-stroke engines, the moving parts are lubricated with a fuel–lubricant mixture. As long as the engine is running, the fuel and lubricant burn together. The combustion of this fuel–lubricant mixture can adversely affect exhaust emissions and cause excessive carbon deposits on the spark plug. In this paper, experiments were carried out using different amounts of oil (100:3, 100:3.5, and 100:4 vol.) in a two-stroke gasoline-powered generator. In addition, we attempted to improve the lubricant’s properties by adding hBN (0.5% vol. or 1.3% wt.) to the lubricant. It was observed that the flash point and pour point did not change as a result of the addition of hBN to the lubricant, and the density and viscosity index increased linearly depending on the amount of hBN. In a series of experiments, the generator was examined for performance and emissions. With the addition of hBN, there was a significant decrease in the specific fuel consumption and exhaust gas temperature, the CO₂ increased, and the CO and HC decreased. These results show that hBN improves combustion. As a result, it was reported that reducing the amount of lubricant leads to increased emissions and decreased performance. It was found that when 0.5% hBN by volume is added to the lubricant, the lubricating property improves, and thus, the amount of oil added to the fuel can be reduced to an acceptable level (from 100:4 to 100:3.5) without causing mechanical failure in the engine.

The heat values of waste mineral oils are equal to the heat value of the fuel oil. However, heat value alone is not sufficient for the use of waste minerals oils as fuel. However, the critical physical properties of fuels such as density and viscosity need to be adapted to the system in order to be used. In this study, the engine oils used in the first 10,000 km of the vehicles were used as waste mineral oil. An organic-based Mn additive was synthesized to improve the properties of the waste mineral oil. It was observed that mixing the Mn additive with the waste mineral oil at different doses (4, 8, 12, and 16 ppm) improves the viscosity of the waste oil and the flash point. The resulting fuel was evaluated for emission using different loads in a 5 kW capacity generator to compare the fuel with standard diesel fuel and to determine the effect of Mn addition. In the experimental study, it was observed that the emission characteristics of the fuel obtained from waste mineral oil were worse than diesel fuel, but some improvement was observed with Mn addition. As a result, we found that the use of waste mineral oils in engines in fuel standards was not appropriate, but may be improved with additives.

Tr en Trafikteki taşıt sayısının artması ile birlikte trafik akışı için birçok senaryo oluşturulmaktadır. Bununla birlikte taşıtların trafikteki bekleme süreleri de sürekli artmaktadır. Yanlış tasarlanmış bir trafik planı trafik sıkışıklığına ve çevresel problemlere neden olmaktadır. Bu çalışmada dört fazlı bir kavşaktaki çevresel etkilerin incelenebilmesi için CO2 eşdeğeri emisyon değerleri (karbon ayak izi) hesaplanmıştır. Kavşaktaki CO2 eşdeğeri emisyonunun hesaplanabilmesi için eşitlikler türetilmiştir. Bu hesaplamalar yapılırken rölanti stop-start sisteminin ve elektrikli taşıt sayısının etkisi de bir gelecek senaryosu olarak ele alınmıştır. Yapılan çalışma neticesinde elektrikli taşıt sayının az miktarda değişimi, kavşakta oluşan CO2 eşdeğeri emisyonunu önemli derecede azalttığı görülmüştür. Bununla birlikte rölanti stop-start sisteminin kullanılması ile birlikte CO2 eşdeğeri emisyonun az da olsa azaltılabileceği görülmüştür. With the increase in the number of vehicles in traffic, there are many scenarios for traffic flow. On the other hand, the waiting times of the vehicles in traffic are constantly increasing. A misplaced traffic plan leads to traffic congestion and environmental problems. In this study, CO₂ equivalent emission values (carbon footprint) were calculated in order to examine the environmental effects in a four-phase intersection. Equations were derived to calculate CO₂ equivalent emission at the intersection. The effect of the idle stop-start system and the number of electric vehicles was also considered as a future scenario. As a result of the study, it was observed that the small number of electric vehicles decreased the CO₂ equivalent emission at the intersection significantly. However, with the use of the idle stop-start system, it has been observed that CO₂ equivalent emissions can be reduced.

In this study, a 1D model was created using the Ricardo-Wave program for a single-cylinder, spark ignition, four-stroke, direct injection engine with a stroke volume of 398 cc. Air-fuel ratio (AFR), mixture temperature (MT), and start of injection (SOI) were used as fuel injection parameters. Using these parameters, 343 different cases were created. Brake power, thermal efficiency, and fuel consumption were used as engine performance parameters. By holding one injection parameter constant, a contour plot was created to examine the effect of the other two parameters on the engine performance parameter. According to the results, the effect of MT and SOI on brake power is 1%, the effect of AFR on brake power is 9.6%, the effect of MT and SOI on thermal efficiency is 1%, and the effect of AFR on thermal efficiency is 12.8%. The effect of MT and SOI on fuel consumption is 0.04%, the effect of AFR on fuel consumption is 22.9%, and the effect of AFR on brake specific fuel consumption is 22.9%. These results indicate that the most significant effect is provided by AFR, while MT and SOI also have a slight impact on engine performance.

In recent years, the use of nanoscale additives to diminish the coefficient of friction and regulate wear mechanisms in engine lubricants has emerged as a growing study field. In this study, the tribological performance of 15W-40 diesel engine oil was investigated by adding four different concentrations (25, 50, 100, and 200 ppm) of dispersed boron carbide (B4C) nanoadditive to 25 mL of oil. Friction and wear tests were performed under limiting lubrication conditions using a tribometer (20 N load, 500 m sliding distance). SEM/EDS analyses were conducted to evaluate the coefficient of friction, wear rate, and surface topography. The results show that the base oil exhibited the lowest average COF (0.112), friction force (2.24 N), and wear loss (0.0055 mm3), whereas the B4C-containing lubricants showed higher average COF (0.129-0.197), friction force (2.58-3.94 N), and wear loss (0.0285-0.0355 mm3) with increasing additive concentration from 25 to 200 ppm. Under the present test conditions, B4C addition did not improve the tribological performance of the base oil; instead, increasing B4C concentration led to progressively higher friction and material loss.