Study on the influence principle and application law of intake wall thickness on uniflow scavenging opposed-piston engine

Abstract

Energy efficient utilization is an important research direction of energy conversion systems. Uniflow scavenging opposed-piston engine has the potential to achieve higher thermal efficiency than classic engines. The lack of valve mechanism leads to the poor scavenging performance of uniflow scavenging opposed-piston engines. Many studies have been conducted to improve scavenging performance by optimizing intake structure. However, the critical influence of intake wall thickness has not been considered. Therefore, a three-dimensional simulation model of intake wall thickness was established and validated. Then the detailed influence of intake wall thickness was explored. Last, the influence law of intake wall thickness under different application conditions is explored. According to the simulated results, intake wall thickness significantly affects the scavenging process by influencing exhaust gas backflow and changing the scavenging passage; the vital influence of intake wall thickness should be considered in optimizing other intake structures. Thicker intake wall thickness increases the backflow resistance and retains more exhaust gas backflow in the intake port, which is conducive to orderly cleaning backflow exhaust gas. The thinner intake wall thickness should be selected at small intake pressure, and the thicker intake wall thickness should be selected at large intake pressure.