Three-Dimensional Laser Doppler Anemometer(LDA) Measurements in an Aero-Engine Bearing Chamber


For future efficient and light aero-engines it is essential to develop optimized lubrication systems. These systems require increased temperature and pressure levels in combination with high rotational speeds without compromising the high level of safety and reliability. This applies especially to the bearing chamber as one of the most challenging components of the oil system. Due to the mixing of the sealing airflow and the lubrication oil a complex air- / oilflow is formed inside the chamber. In order to gain a deeper insight into the physical phenomena of the flow inside the bearing chamber a multiyear fundamental study has been initiated. This study focuses for the first time on detailed measurements of the local air- / oilflow field.
In the first phase of the project experiments have been carried out to determine the rotating and swirling pure airflow. Hence a specially adapted three dimensional Laser Doppler Anemometry(LDA) system was used to resolve the complex flow. The results revealed that different flow patterns occurred depending on the ratio between the shaft speed and the airflow rate. In the near future it is aimed to resolve the droplet flow also to provide a complete knowledge of the air- / oilflow in bearing chambers.