Virtual design of a novel two-stroke high-speed direct-injection diesel engine

Abstract

The paper reviews the virtual design process of an automotive high-speed direct-injection (HSDI) two-stroke diesel engine, developed at the Department of Mechanical and Civil Engineering (DIMeC) of the University of Modena and Reggio Emilia. The new concept of the engine is the tumble-supported and spray-controlled combustion system, which enables the adoption of loop scavenging without valves, and the use of a very simple and compact combustion chamber, carved in the engine head. The concept has been applied to a three-cylinder engine, with a capacity of 1050 cm3, supercharged by means of a Roots compressor and a variable geometry turbocharger. Some alternative configurations have been defined. Integrated one-dimensional and multidimensional computational fluid dynamics (CFD) simulations have been performed in order to optimize the main engine parameters, as well as to predict brake performance and emissions, in comparison with a reference four-stroke automobile diesel engine. Simulation results demonstrate the potential of the concept, which may be applied to develop a new generation of ultra-compact and clean automotive diesel engines.