Abstract
With lubricated systems in engine, it is current to observe oil leakage, particularly in conduits that follow component assembly interfaces. When these are located within the engine and lead to no external leakage, this leakage is both hard to observe and to quantify. In theses cases the designer must appreciate the leakage rate through the gaps due to clamping imperfection, and estimate their influence on the reduction of downstream pressure. Although this question is frequent in hydrodynamic bearing feed design for example, it is difficult to find related articles in the literature. The usual way to solve this problem is to estimate loss of pressure in relation to singular pressure drop representing the leakage.
The target of this article is to present new design tools elaborated from physical investigations. The advantages of this tool are a better physical understanding of the phenomena and an easy use particularly interesting during the pre-design period. The first part is a modification of the Reynolds equation to take into account distributed leakage. This new equation is numerically solved for different gap distributions. In the second part, a criterion is formulated for minimum required pressure. This criterion also comes from physical models and experience. Such a criterion allows to avoid the use of CFD calculations which are not suitable for quick design.