Effects of oil aeration in engine can lead to several problems such as oil compressibility, reduced cooling effect, reduced lubrication, etc. It is then important for engine and oil manufacturers to know the level of oil aeration in different condition of engine use.
DSI-Deltabeam has developed a new device, called “Air-X”, which allows on-line measurement of oil aeration while the engine is running. It performs a continuous oil density measurement, which is automatically converted to aeration taking into account temperature and pressure effects. The device offers a very short response time in the range of several seconds and it can be connected anywhere in the engine oil circuit for continuous sampling, making it possible to study on-line the impact of engine parameter changes such as engine speed, torque, temperature, etc. on oil aeration. The device is also equipped with a qualitative visualization system helping for understanding the phenomena as oil aeration can be present in different type of forms (bubbles, foam,…).
The paper describes the operating principle of the new instrument and presents measurement results obtained with a specific engine, for various operating conditions. It also compares the influence of several parameters such as oil formulation and temperature on oil aeration.