Abstract
Eco-friendly fluids in the hydraulic sector are becoming more and more relevant, under the current and future stringent environmental regulations by US EPA and European Committee. Biodegradable fluids have very interesting characteristics, and the literature starts reporting some contributions focused on components performance. The current article represents a contribution that brings the focus on the hydraulic poppet valves.
The article is based on a particular experimental technique that allows full optical insight on cavitation inception and development with simultaneous analysis of the steady flow rate, improving the classical technique of Oshima et Al.
Two market available eco-friendly fluids and a standard one are tested on a reference poppet valve layout. The experimental investigations are carried out by exploring the valve operation range in terms of pressure drop and poppet opening. The optical investigations are based on high-speed imaging, which allows to observe the behaviour of cavitating regions. The steady discharge flow coefficients are provided, and cavitation inception/development is characterized. The results related to the eco-friendly and to the standard fluids are compared, supporting the analysis of the influence of the new fluids on the discharge flow. The results on cavitation inception and development provide useful data for valve design and for validating three-dimensional models of cavitating flows.
