Calculation of Flow in the Piston-Cylinder-Ring Crevices of a Homogeneous-Charge Engine and Comparison with Experiment

Mathematical Model of Piston Ring Sealing in Combustion Engine

“…μ -dynamic gas viscosity determined from the relation [13]: The lock cross-section area A was approximated by a rectangle of the dimensions a x b, with taking into account the area A+ which may result from e.g. bevels of ring end edges (Fig.…”

“…In the obtained model the behind-ring and inter-ring spaces were considered separately by applying a series -parallel scheme of the labyrinth. Such labyrinth scheme is commonly used in the integrated models [13,9,26,10,28,30].…”

“…At determining axial ring displacements the following was taken into account: force resulting from gas pressure under and over the ring, inertia force as well as friction force between ring and cylinder liner, determined from an empirical relation. Only axial displacements were taken into account in the models [13,20,10,11]. Tian et al [26] developed an improved version of the model [18], considering ring twisting motion.…”

“…In the majority of models [2, 4,27,17,18,13,31,20,1,22] it was assumed that cross-sections of gas flow through ring lock and spaces of labyrinth stages are constant. In actual engine, volumes of inter-ring and behind-ring spaces , and especially cross-sections of gaps in locks , may change within a broad range during one cycle of engine work due to displacing motion of the piston together with rings along cylinder liner of a variable diameter.…”

“…In the integrated models of gas flow and ring dynamics it is commonly assumed that cross-sections of channels between ring and groove result from an instantaneous position of ring against groove [18,13,9,26,10,28,11].…”