双作用斯特林热机活塞密封流阻特性数值计算

考虑活塞前部环形间隙的影响，建立斯特林发动机活塞密封结构的流阻模型，分别展开动、静态下数值计算，得到活塞各密封段内压力与流量的关系，分析工质随结构参数变化的流动特性。结果表明：动、静态下活塞密封处流阻呈现不同特点，动态时流阻随流量增加而增大，静态时流阻为一恒定值；活塞环泄漏面积对流阻的影响较大，可以通过使用组合式活塞环以增大流阻而减小泄漏；而前部间隙宽度对流阻的影响较小，适当加大间隙宽度能在不影响密封的前提下减小活塞与气缸的摩擦。

Numerical Calculation of Flow Resistance Characteristics of Double-acting Stirling Engine Piston Sealing

Considering the influence of front piston annular gap,the Stirling engine piston seal structure model of flow resistance was established,and the static and dynamic numerical calculation was carried out.The relationship between pressure and flow rate in each sealing part of piston was obtained,and the flow characteristics of the working medium changing with the structure parameters was analyzed.The results show that the dynamic and static flow resistances of the piston seal show different characteristics,with the increasing of flow rate,the dynamic flow resistance is increased,and the static flow resistance is a constant.The piston ring leakage area has a large influence on flow resistance,a composite piston ring can be used to increase the flow resistance and reduce the leakage.The front gap width has a small influence on flow resistance,the friction of piston and cylinder can be reduced by increasing the gap width without affecting the piston seal.