Prediction of IC Engine Power System Durability with the Use of Ring Pack Model

Grzegorz Koszałka,Andrzej Niewczas

doi:10.2478/v10040-008-0156-x

Abstract

Prediction of IC Engine Power System Durability with the Use of Ring Pack ModelThe paper presents the new method of engine life prediction, which bases on the results of wear measurements taken on an investigated engine and simulations carried out with the use of the analytical model of ring pack of the engine. In the contrary to traditional methods the proposed method does not require the prior knowledge of the limit wear value, which is essential for the prediction, however its reliable establishing for new engines is difficult. In the presented method its value is determined with the use of the ring pack model. The example of durability calculation for an automotive diesel engine is also presented.

Highlights

Piston-rings-cylinder assembly (PRC) is a basic functional system of an internal combustion engine, and its most significant function is to guarantee tight, movable closing of the combustion chamber
The first condition is fulfilled if operating conditions of the engine during the research do not lead to the different wear, in quality terms, from that met in reality, and if wear course is determined on the basis of measurements made on the engine which has undergone its run-in period
Presented method of durability prediction bases on empirically determined intensities of wear of piston kit components and on the results of simulations made with the use of the analytical model of the ping pack

Summary

Introduction

Piston-rings-cylinder assembly (PRC) is a basic functional system of an internal combustion engine, and its most significant function is to guarantee tight, movable closing of the combustion chamber. Boundary wear is usually determined in the described way on the engines which are at least one generation older than the ones for which the durability is forecasted Another shortcoming of empirical models of boundary state (statistically determined values of wear for objects withdrawn from service) is that they do not allow for more detailed analysis of causes of the tightness drop – for instance how wear of particular components and increase of individual clearances affects the tightness. Taking above into consideration the authors decided to use analytical model of the ring pack for determination of the boundary wear This model describes cause and effect relations between dimension of particular clearances and blowby intensity and allows for evaluation of tightness changes caused by wear. Analytical models have already been successfully used for analyzing of ring pack operation and improving the design (Keribar, et al, 1991; Tian, et al, 1998; Tian, 2005; Wolff, 2009)

Analytical model of piston ring cylinder kit

Method of durability prediction

Example of calculations

Findings

Conclusion