The effect of oil temperature on cavitation inception and development in V-notched hydraulic valve orifices

This study investigates the effects of oil temperature on cavitation inception and intensity in a hydraulic orifice. A two-dimensional visual experimental model was designed based on a V-notched spool valve. Cavitation inception and development across various oil temperatures were captured using high-speed imaging and analyzed via grayscale analysis. By applying the Bunsen solubility principle, a curve-fitting model was developed to correlate the cavitation inception pressure with the orifice pressure differential for hydraulic oil containing dissolved air; this correlation was validated through air separation pressure measurements. Furthermore, the experimental results establish an equivalence between cavitation induced by an increase in oil temperature and that caused by an increased pressure differential. Specifically, a temperature increase of 10 °C from baseline temperatures of 20, 30, 40, and 50 °C was found to produce cavitation enhancement equivalent to that caused by increasing the pressure differential by 2.0, 2.0, 1.5, and 1.0 MPa, respectively. It is important to note that this quantitative relationship was obtained under the specific conditions of the V-notched valve orifice geometry and the L-HM46 anti-wear hydraulic employed.