Fluid-Dynamic Analysis of a High-Performance Engine Lubricant Circuit

摘要

Modern internal combustion engines are the result of several years of designing to meet the growing demand of high specific power, low fuel consumption and low exhaust emissions. Nowadays, the running conditions are becoming more and more demanding and therefore modern engines must provide high performance in a variety of operating conditions like cold start, frequent start and stop, long time high speed and load. Consequently, all the components and auxiliary systems work under onerous conditions. In particular, the lubrication system is highly stressed because these circuits must also supply other components, for example, the variable valve timing (VVT) actuation system. To satisfy these demanding situations, a lot of advances in lubrication technology have been achieved and more work is still needed. Hence a design optimization of the engine lubrication circuit and of its components, is becoming more important, due to the necessity to combine efficiency with a rational management of energy consumption. In this paper, the authors present an optimized design methodology of lubricant circuit components. This methodology is based on a modelling approach which uses a numerical fluid-dynamics 1D code (commercial code -^sImagine AMESim) and aims to be a useful tool for the lubricant circuit designer. Moreover, this modelling approach could be an interesting support during experimental measurements, to estimate some parameters (i.e., flow rate) that are not easily measured in every engine point. This fluid-dynamic model has been proposed to describe the complex architecture of lubrication circuit of the Ferrari 8 cylinders dry sump engine and it has been validated by comparison with experimental data. This paper represents an advancing step in the development of new engines and automotive engineering knowledge.