Study of an Air-Oil Pump and Separator Solution for Aero Engine Lubrication Systems

Abstract

Lubrication system of aero engines have to manage a two-phase flow of oil and air created in air-sealed bearing chambers. A part of this flow goes through scavenge pumps and a de-aerator before returning to the tank, the other part passes through a de-oiler before leaving the engine. The Aero-Thermo-Mechanics Department of Université Libre de Bruxelles is developing an original and integrated system to pump and separate a liquid-gas flow. This system helps to reduce the complexity and the oil consumption of aero-engine lubrication systems by replacing the de-oiler, the de-aerator and scavenge pumps. The prototype is composed of an axial part (blades and metallic foam) that performs the separation and a radial part that pressurize the liquid. De-oiling efficiency is measured with a radio-tracer measurement system. This paper presents the test results of four configurations (different radii, flow paths, size of the metallic foam). Droplet size measurements at the inlet and the outlet of the prototype are also presented. A physical interpretation has been developed and is presented.