EXPERIMENTAL AND NUMERICAL STUDY OF THE IMPACT OF THE OIL TANK FILLING LEVEL ON THE AIRCRAFT SEPARATOR

This paper presents a CFD analysis of an air-oil separator of an aircraft gas turbine engine with a focus on the impact of the oil tank filling level on the separator performance for a selected point of the flying mission. The separator efficiency and the oil quality affect the efficiency of the oil system. New design criteria and standards require a better understanding of the phenomena occurring in the separator. To optimize its structure, the flow of the air-oil mixture must be modeled in the design process. Although many papers are addressing the issue of gas-liquid separation, very little knowledge is available on the flow ratio typical of aircraft turbine engines. The separation phenomena were investigated using the volume-of-fluid method. Transient calculations were performed at a selected mission point of the separator and compared with experimental data. A mesh independence study using a structural mesh is included to understand the mesh impact on the analysis results. The current analysis results will support further studies focusing on an optimization analysis where a proper mesh, an adequate turbulence model and an appropriate oil level have to be selected.