Numerical investigation of switching features of a hydraulic seat valve with annular flow geometry

ABSTRACT

This article presents a numerical framework for investigating transient features of hydraulic valves, specifically poppet type designs suited for digital hydraulics. The objective is to determine the validity of the state-of-the-art lumped parameter models (LPM) of fluid dynamical phenomena during switching of such valves. Knowledge about analytically valid models for simple situations are used together with complex Computational Fluid Dynamics simulations, which is not a novel concept, but the procedure at which this is done is. The idea behind the research is to consider a numerical framework with dynamic capabilities as a sufficiently accurate representation of reality. Thereby, strategic simulation cases can be applied to understand the features of the design. The sought dependencies of the valve was revealed by conducting several ‘experiments’ through the simulation framework which allows analysis of practically difficult operating conditions. The results of the numerical framework reveals how and where the state-of-the-art LPM deviate (e.g. that fluid displaced by the plunger itself is not directly proportional to velocity, that fluid inertia is significant and that the fluid-induced force is non-linear with changes in velocity).

KEYWORDS:

• Digital hydraulics
• hydraulic valves
• computer aided analysis
• design methodology

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work is funded by the Danish Council for Strategic Research via the HyDrive-project (case no. 1305–00038B). The authors are grateful for the funding.

Notes on contributors

Niels Christian Bender

Niels Christian Bender received his B.Sc. and M.Sc. degrees in mechatronic control engineering from Aalborg University, Aalborg, Denmark, in 2014 and 2016 respectively. Since 2016 he has been a Ph.D. fellow at the Department of Energy Technology, Aalborg University, with a research focus on design of digital hydraulic on/off valves.

Henrik Clemmensen Pedersen

Henrik Clemmensen Pedersen has been Associate Professor at the Department of Energy Technology, Aalborg University, Aalborg, Denmark, since 2009 before becoming Professor at the same department in 2016. His research interests include analysis, design, optimisation, and control of mechatronic systems and components, with special focus on fluid power systems for wind and wave energy applications. He is an author of more than 100 papers in international journals and conferences.

Bernd Winkler

Bernd Winkler obtained his Bachelor’s degree in Mechatronics in 2000 and doctoral degrees in 2004 both from the Johannes Kepler University in Linz, Austria. He has been an employee of Linz Center for Mechatronics (LCM) GmbH since 2005. Currently he serves as the Business Unit Manager and head of Advanced Hydraulic Drive in LCM GmbH.

Andreas Plöckinger

Andreas Plöckinger obtained his Bachelor’s degree in Mechatronics in 2001 from the Johannes Kepler University in Linz, Austria. He has been an employee of Linz Center for Mechatronics (LCM) GmbH since 2002. Currently he serves as a Senior Researcher in LCM GmbH focusing on integrated electro-hydraulic hybrid drives.