International Journal of Emerging Technology and Advanced Engineering Website: www.ijetae.com (ISSN 2250-2459, ISO 9001:2008 Certified Journal, Volume 4, Issue 8, August 2014) 122 Experimental Investigation of the Performance of VCR Diesel Engine Fuelled by NM-Diesel blend Chandan Kumar 1 , Manish Bafna 2 , Ashish Nayyar 3 , Ved Parkash 4 , Nitin Goyal 5 1,2 Mechanical Engineering Department, Jodhpur Institute of Engineering & Technology, Jodhpur 3,4,5 Mechanical Engineering Department, Swami Keshvanand Institute of Technology, Jaipur Abstract - Increasing the consumption of fuel in power and automobile sector, increase the pollution of the environment. Smoke and NOx are main pollutants of emission from diesel engine and it is very difficult to control them simultaneously. A preliminary literature review suggests that smoke and NOx can be reduced by adding additives in diesel. But some additives are very costly and not vible because they reduce smoke and NOx while decreasing the performance of combustion. In the present study Nitromethane (NM) (2%) was used as an additive with diesel, and investigate the performance characteristic of it on compression ignition engine (A single cylinder, direct ignition, four stroke, vertical, water cooled, naturally aspirated, variable compression ratio diesel engine). The performance and emission characteristics of the engine run on diesel at compression ratio 17.5:1 were evaluated and compared with engine operating on NM-Diesel blend at compression ratio 17.5:1 and16.5:1. The performance has been studied and compare for diesel and NM- Diesel blend for two compression ratios. Keywords- NM-Diesel, VCR diesel engine, acetone. I. INTRODUCTION The objective of this dissertation is to investigate the performance and emission characteristic of a VCR diesel engine fuelled by NM-Diesel blend. Worldwide increase of demand for diesel fuel and environmental emission control has led to considerable research for better fuel formulations and thus reduction in smoke and particle levels. Overtime advances in engine design reduced the emission levels considerably. However, it is difficult to achieve the required emission standards with engine improvements alone. Blending the diesel with different additives has proven to be an alternative method to achieve the low emission and better performance diesel combustion. This has been the focal point of most researches in this field within last two decades. India’s environment is constantly under the increasing pressure imposed by the rapid urbanization coupled with the rapid growth in the population. Increasing population, leading to an increase in number of vehicles and growth in the industrial and power sectors are exerting tremendous pressure on the atmosphere. Major polluting industries and automobiles emit tonnes of pollutants every day, thereby leading to the deterioration in air quality and exposing citizens to greater health risks. 1.1 Health Effects of Diesel Engine Emission Diesel emission has the potential to cause adverse health effects. These effects include cancer and other pulmonary and cardiovascular diseases. Diesel exhaust, in addition to generating other pollutants, is a major contributor to particulate matter pollution in most places in the world. More recently the possible effects of fine particles below 10 μm on respiratory morbidity and mortality, especially in subjects with established chest disease, have been broached. It is apparent that exposure to diesel fumes in sufficient concentrations may lead to eye and nasal irritation but there is no evidence of any permanent effect. There is also some evidence that the chronic inhalation of diesel fumes leads to the development of cough and sputum. Higher exposures may lead to acute symptoms, primarily affecting the conjunctivae and upper respiratory tract that is nearly always reversible within a few days. The human health effects of poor air quality are far reaching, but principally affect the body's respiratory system and the cardiovascular system. 1.2 Additives So many additives are readily available to prepare blends with diesel and used in CI Engines. Among the various additives, oxygenated compounds are the most widely used. This is due to the participation of their oxygen in reactions and leading to a better combustion thus lowering the emissions. The molecular structure and oxygen content of the additives have a direct influence on soot reduction. This also depends on the oxygen concentration in the fuel plume. The results revealed that in order to reduce soot formation, 10–20% volume of oxygenate chemicals should be blended with diesel fuel. The presence of additives in such a high quantity will alter the physical and chemical properties such as: viscosity, density, volatility, and the cetane index, significantly. Nitroparaffin compounds have high oxygen content in their molecular structure. Therefore, they are considered as oxygenated additives.