Experimental investigation of the emission and performance of preheated and unheated garlic methyl ester fuels and diesel fuel in a diesel engine

t is thought that vehicles running on diesel fuel significantly impact climate change in the world. To reduce this negative effect, changing the fuel source without making any changes to the engines is a very attractive method. Considering the environment, climate change, living health, and the lifespan of fossil fuels, studies on biodiesel fuels, which can be an alternative to diesel fuel, are important. In the present study, garlic methyl ester (GME) was produced from crude garlic oil using the transesterification method. The impacts of preheated and unheated GME and its blends on a diesel engine with an air cooling system without any modification were researched. GME was used with diesel at 20% and 60% volumetric ratios and was also used at 100%. Experimental studies were conducted at five engine loads (1, 1.5, 2, 2.5, and 3 kW). The GME and its blends were tested at the specified loads, and the results were obtained. The GME and blends were then preheated at 70 degrees C, and the experimental studies were repeated under the same conditions. In the tests, NOx, CO, CO2, HC, smoke density, EGT, BSFC, in-cylinder pressure, engine torque, noise, vibration, and thermal image analyses were conducted. According to the results, CO 22.3%, HC 24.9%, smoke density 25.6%, torque 4.6%, cylinder pressure 5.2%, and EGT 11.5% decreased, whereas BSFC 11.2%, noise 1.4%, vibration 3.8%, CO2 6%, and NOx 18.2% emissions increased in GME and its blends compared to diesel. The highest measurement values were obtained with 100% GME fuel. It was observed that both increasing the GME ratio and the preheating process improved the emission and performance values. The results obtained show that GME and its blends can be easily used in diesel engines without any modification