Abstract
Keywords- CO2 Emissions, Vehicle Simulation, Downsizing, Gasoline Direct Injection, Mild Hybrid
The EU set a new target of 130 g CO2/km for the NEDC test in 2012 and will support research efforts aimed at further reducing emissions from new cars to an average of 95g CO2 /km by 2020.
To assist the OEMs to reach this ambiguous goal by maintaining end customer comfort and fun-to-drive, it is necessary for the supplier industry to understand and to optimize the functional interactions between the different vehicle and power-train components and the related control functions. Finally, the reactions of the vehicle system to different user profiles have to be taken in account.
This optimization and integration process needs increasingly the integration of different competences found within the OEMs, engineering companies and the different sub-system and component suppliers.
To increase the added value of the products and services supplied, Continental teamed up with Lotus Engineering in a project aiming at a better understanding and control of this integrated approach to develop improved engine design and system integration support. In a first step, Continental developed a simulation tool to asses the energy balance within the vehicle taking in account all physical processes and subsystems: the combustion engine, mechanical friction, the fuel system, thermal management including water and oil circuit and the electrical loads for different levels of hybridization. Some results are presented. Based on this model, a production vehicle was chosen and equipped with a new prototype engine developed and supplied by Lotus within this cooperation project.
The integrated design process for the engine hardware, the engine management system and the auxiliaries allowed the development and the realization of this prototype power-train in a very short time from white sheet to chassis dynamometer testing.
The engine concept chosen is a 3-cylinder, 1.5 litre turbocharged engine with direct gasoline injection in central position, an integrated exhaust manifold, homogeneous combustion, double VVT and valve lift switching on the inlet valves. After engine dynamometer calibration, the engine has been implemented in the base vehicle. The power-train features also an electrical water-pump and a crankshaft mounted electrical motor for a mild hybridization. The hybrid concept includes electrical energy storage by double layer capacitors.
The vehicle has been calibrated for NEDC and driveability. The concept shows very competitive results in terms of fuel consumption.
The vehicle concept is presented, together with engine results for part load and full load as well as vehicle results for the NEDC.