THE INFLUENCE OF THERMODYNAMIC STATE OF MINERAL HYDRAULIC OIL ON FLOW RATE THROUGH RADIAL CLEARANCE AT ZERO OVERLAP INSIDE THE HYDRAULIC COMPONENTS

Main Article Content

Darko M. KNEŽEVIĆ Aleksandar N. MILAŠINOVIĆ Zdravko N. MILOVANOVIĆ Saša S. LALOŠ

Abstract

In control hydraulic components (servo valves, LS regulators, etc.) there is a  need for precise mathematical description of fluid flow through radial clearances between the control piston and body of component at zero overlap, small valve opening and small lengths of overlap. Such a mathematical description would allow for a better dynamic analysis and stability analysis of hydraulic systems. The existing formulas in the literature do not take into account the change of the physical properties of the fluid with a change of thermodynamic state of the fluid to determine the flow rate through radial clearances in hydraulic components at zero overlap, a small opening, and a small overlap lengths, which leads to the formation of insufficiently precise mathematical models. In this paper model description of fluid flow through radial clearances at zero overlap is developed, taking into account the changes of physical properties of hydraulic fluid as a function of pressure and temperature. In addition, the experimental verification  of the mathematical model is performed.

Article Details

How to Cite
KNEŽEVIĆ, Darko M. et al. THE INFLUENCE OF THERMODYNAMIC STATE OF MINERAL HYDRAULIC OIL ON FLOW RATE THROUGH RADIAL CLEARANCE AT ZERO OVERLAP INSIDE THE HYDRAULIC COMPONENTS. Thermal Science, [S.l.], v. 20, p. S1461-S1471, feb. 2017. ISSN 2334-7163. Available at: <http://thermal-science.tech/journal/index.php/thsci/article/view/1663>. Date accessed: 18 oct. 2017. doi: https://doi.org/10.2298/TSCI16S5461K.
Section
Articles
Received 2017-02-07
Accepted 2017-02-07
Published 2017-02-07

References

[1] Bašta, T. M., Mašinska hidraulika, (Mechanical Hydraulics – in Serbian), Faculy of Mechanical Engi- neering, Belgrade, 1990
[2] Borghi, M., et al., Analysis of Hydraulic Components Using Computational Fluid Dynamics Models, Proceedings of the Institution of Mechanical Engineers, Part C: Journal of Mechanical Engineering Science, 212 (1998), 7, pp. 619-629
[3] Wu, D., et al., An Empirical Discharge Coefficient Model for Orifice Flow, International Journal of Fluid Power, 3 (2002), 3, pp. 13-19
[4] Knežević, D., et al., Mathematical Modeling of Changing of Dinamic Viscosity, as a Function of Tempera- ture and Pressure, of Mineral Oils for Hydraulic Systems, Facta Universitatis, 4 (2006), 1, pp. 27-34
[5] Stachoviak, G., et al., Engineering Tribology, University of Western Australia, Perth, Australia, 2001
[6] Keith, P., et al., Hydraulic Fluids, Arnold, UK, 1996