Concept Design And Analysis For An Innovative Two Stroke Spark Ignition Engine With New Exhaust Valve And Intake System

The overall height and weight of the traditional four-stroke piston engine is difficult to reduce dueto the existence of crank and connecting rod, which directly worsen the engine’s compact design andlightweight design. Therefore, an engine with layout of the new structure with high thermalefficiency pre-study has important implications.In this paper, based on the foreign NEVIS engine patent and researches about other prototypesrelated, the NEVIS engine structure characteristics are designed in concept and analyzed, especiallythe non-rod structure, the large bore chamber, the new exhaust valve and intake system, the variablecompression ratio regulation device structure and the exhaust valve timing regulation devicestructure. The main contents are as follow:1. The NEVIS engine structure analysis: To analyze the NEVIS engine structure characteristics, toestablish major structural model of the engine with the use of three-dimensional modeling software,and to analyze its structure, work processes and how it works;2. The engine in-cylinder thermodynamic work process of mathematical modeling and simulation:The engine in-cylinder thermodynamic work process mathematical model is set up, and the basicthermodynamic differential equations, the engine in-cylinder volume variation, the heat release rateand cylinder peripheral wall heat transfer are analyzed via Simulink of MATLAB;3. The NEVIS engine predicted performance evaluation: Comparing the NEVIS engine and thetraditional four-stroke spark ignition piston engine at a constant speed and under different loads, theeconomy and power indicators are predicted.The above results set up a theory foundation of the design for an innovative engine with acombination of the layout of the new structure and highly efficient thermodynamic cycle.