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Off-road BS III CEV (US-TIER III equivalent) emission regulations for diesel engines (i.e. Construction Equipment Vehicles) in India demands a technology upgrade to achieve a large reduction in NOx (>50%) and Particulate Matter (>50%) compared to BS II CEV emission levels. EGR is a widely accepted technology for NOx reduction in off-road engines due to lower initial and operating costs. But EGR has its own inherent deficiency of poor thermal efficiency due to lack of oxygen and further increase in soot adding complexity of meeting PM Emissions. Hence an engine meeting BS III CEV norms without EGR/SCR technologies with low initial investment is most desired solution for Indian off-road segment. This work deals with the development of an off-road diesel engine rating from 56 to 74 kW, focused mainly on in-cylinder optimization with the aid of optimum injection and charging strategies.

This study deals with the development of an internal EGR (Exhaust Gas Recirculation) system for NOx reduction on a six cylinder, turbocharged intercooled, off-road diesel engine based on a modified cam with secondary lift. One dimensional thermodynamic simulation model was developed using a commercially available code. MCC heat release model was refined in the present work by considering wall impingement of the fuel as given by Lakshminarayanan et al. The NOx prediction accuracy was improved to a level of 90% by a generic polynomial fit between air excess ratio and prediction constants. Simulation results of base model were correlating to more than 95% with experimental results for ISO 8178 C1 test cycle. Parametric study of intake and exhaust valve events was conducted with 2IVO (Secondary Intake Valve Opening) and 2EVO (Secondary Exhaust Valve Opening) methods. Combinations of different opening angles and lifts were chosen in both 2IVO and 2EVO methods for the study.

The present work describes an approach to predict the vehicle fuel economy by simulating its engine drive cycle on a transient engine dynamometer in an engine testbed. The driving cycles investigated in the current study were generated from the typical experimental data measured on different vehicles ranging from Intermediate Commercial Vehicle (ICV) to Heavy-duty Commercial Vehicle (HCV) in real-world traffic conditions include various cities, highways and village roads in India. Reliability and robustness of the method was studied on various engines with cubic capacity from 3.8 liters to 8 liters using different drive cycles, and the results were discussed. Later, using same measured drive cycles, vehicle fuel economy was predicted by a vehicle simulation tool (AVL CRUISE) and results were compared with experimental data. In addition, engine coolant temperature effect on fuel economy was investigated.