DEVELOPMENT OF A SOLENOID BASED VALVE CONTROL SYSTEM FOR SIX AND EIGHT-STROKE INTERNAL COMBUSTION ENGINE

ABSTRACT The growing need to achieve more efficiency and better flexibility in internal combustion engines has aroused interest in alternative valve actuation systems that might enable the unconventional engine cycles of six- and eight-stroke operation. Traditional cam-follow poppet valve systems are necessarily restricted in their ability to follow arbitrary mechanical profiles, and therefore they are limited in their ability to follow extended-stroke cycles, characterized by irregular and cycle-dependent valve events. The report offers the design, development and experimental analysis of a solenoid-operated valve system as one of the initial stages in providing a flexible valve control to multi-stroke internal combustion engines. This research paper starts by thoroughly reviewing the history of the internal combustion engines, the traditional valve actuation mechanisms, and the history of variable and camless valves. The additional focus is laid on valve timing requirements and control difficulties linked with six and eight stroke engine cycles that form the impetus of electronically actuated valve systems. According to this review, there were functional requirements on the speed of actuation of valves, consistency of lift, repeatability and control flexibility. A systematic design approach was taken, which consisted of define, design and demonstrate. The mechanical design was concerned with the creation of a solenoid-based valve actuation system through a normally closed pneumatic solenoid valve whose body is made of zinc alloy. Autodesk fusion 360 was used to create conceptual, preliminary, and detailed mechanical designs making sure that they had the same dimensions, had proper clearances and could actuate reliably. To provide controlled assessment of actuation time, regardless of a camshaft mechanism, an electronic control system based on Arduino was applied to control the opening and closing of the valves. Experimental testing to determine valve actuation performance in non-flow conditions was done focusing on the response time in opening and closing, reproducibility of stroke, electrical behaviour and thermal properties of operation over a long period. Long ON-time actuation tests were also specifically used to test worst-case thermal loading and actuator stability. Consistent valve response measurement, repeatable actuation behaviour and evident differences between commanded and measured actuation timing were shown to be due to solenoid dynamics. Thermal tests indicated a gradual increase of coil temperature with continuous operation which points out to viable constraints of non-steam-rated solenoids in long duty cycles. The findings validate that solenoid-powered valve actuation has much more time flexibility than the traditional cam-driven poppet valve systems, especially in the case of alternative multi-stroke engines. Limitations with regard to response time, thermal performance and fluid compatibility were however befriended. The study [SF3.1]concludes that even though the developed system is not good enough to directly run on the engine or steam, it is able to verify the viability of the valve actuation as a platform to develop in future. There are suggestions on how to optimize the system in terms of the utilization of steam-rated solenoids, better thermal control, and the incorporation of crank-angle-based control measures. Keywords: Solenoid valve, Camless engine, Valve actuation, Internal combustion engine, Six-stroke engine, Eight-stroke engine, Valve timing, Electromechanical valve, Arduino control, Engine efficiency, Experimental testing, Valve response time, Thermal effects, Actuation.