Fluids with a high proportion of dissolved air lead to an increased air release in hydraulic components. Looking at the fluid flow in a piston pump, the resulting multiphase flow may affect its metering performance. To improve effects caused by cavitation, it is necessary to detect and analyze all critical flow areas in detail.
This paper presents investigations of the multiphase flow in an electromagnetically driven dosing pump. This type of pump is suitable for metering any kind of liquid in motor vehicles in a very precise manner. Using high speed camera equipment and transparent components for the displacement chamber, the presented experimental work gives a comprehensive insight into the most relevant cavitation effects in the pump. In addition, the pressure inside the displacement chamber is measured with the help of a miniature pressure sensor. By combination of measuring data and visual recordings, cavitation phenomena can be determined precisely, so that a profound understanding of the flow behavior in the pump is achieved.