Effect of variable compression ratio on performance and emissions in compression ignition engine fuelled with waste cooking oil with copper oxide nano fluid blends

One of the challenging issues in the world today is waste management. Improper waste management could be the main source of environmental pollution. In this context, an attempt has been made to prevent the disposal of large quantities of Waste Cooking Oil (WCO) from hotels and restaurants and utilize them as a fuel in diesel engines. WCO is one of the viable alternative fuels, used by researchers in Compression Ignition (CI) engines due to its low cost, no toxicity, biodegradability and renewability. In this research, copper oxide (CuO) nano fluids were prepared by an one-step chemical synthesis method in different mass fractions of 15 ppm, 25 ppm, 35ppm and 50 ppm and blended with WCO. Based on the fuel stability, WCOCN25 and WCOCN50 test fuels are considered. The diesel and WCO were considered as base fuels. A fully equipped, single cylinder, four stroke, water cooled, direct injection, variable compression ratio diesel engine was used for experimentation. The compression ratio of the engine was varied from 16:1 to 18:1. The engine was loaded at different loading conditions by an eddy current dynamometer to measure the performance and emission parameters for the test fuels. The experimental results have shown that the addition of CuO nano fluids and increasing the compression ratio improved the Brake Thermal Efficiency (BTE) of the engine. It is observed that the combustion parameters have been improved due to the higher ignition delay and catalytic activity of CuO nano fluids. In addition, CuO nano fluids have a major role in controlling hydrocarbon (HC), carbon monoxide (CO), oxides of nitrogen (NOx) and smoke emissions. © 2021. MechAero Foundation for Technical Research & Education Excellence.