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BS-VI or equivalent development calls for tremendous efforts in concept investigation and calibration for engine out, after treatment, diagnostic checks, off-cycle emissions, field performance, component safety etc. Achieving calibration quality for all these tasks is very challenging considering development time and cost with conventional physical testing approach. Present article focuses on assessment of testing and calibration using virtual approach. To prove and validate this approach, a six-cylinder heavy duty diesel engine is selected and configured in HiL environment. The engine plant model is built offline and validated with base engine data at steady state and transient operations and RT model is integrated with ECU hardware. Data for plant model corrections is generated with short measurement campaign. Refined real time plant model is prepared for evaluating different calibration strategies on virtual test bed environment.

Air pollution in India and also global warming are two major concern in the country. To address this situation, India is moving from BS-IV to BS-VI for on-road applications with 90% reduction in NOx and 50% in PM with limit on particulate number. Also moving to Trem-IV and Trem-V for off-road applications subsequently. It needs higher efficiency after-treatment systems like SCR and DPF to achieve such lower emission levels. Addition of these complex after-treatment system, severely increase the cost of diesel power plant with heavy penalty on fuel economy. Hence, it is challenge to auto industry to reduce the complexity and cost, so that it requires an alternate solution to reduce NOx and PM emissions at source to reduce cost and system complexity. Low Temperature Combustion (LTC) is a potential concept to reduce the NOx and PM emissions simultaneously.

This paper focuses on assessment of different thermal management strategies for heavy duty Diesel(HDD) engine aftertreatment using semi-physical model for both engine and aftertreatment. Aftertreatment configuration of DOC, DPF and SCR is considered for six cylinder HDD engine. SCR reaction kinetics, ammonia adsorption and desorption parameters were calibrated with the data from synthetic test bench. Calibrated aftertreatment model is integrated with semi physical 6-cylinder HDD engine model to validate over steady state as well as transient measurement data. Engine model is modified for different thermal management strategies such as Intake, Exhaust throttle valve, start of main injection, Post injection and evaluated for their impact on performance and emission parameters. Results over operating point are analysed to select best strategy at cold operating zone.