0000000000358709
AUTHOR
Jannik Hartwig Jakobsen
Synthetic Esters and Dynamics of Pressure Compensated Proportional Directional Control Valves
The purpose of this paper is to help reduce the uncertainty in behavior introduced when changing hydraulic oil from mineral oil (HLP) to biodegradable oil (synthetic esters - HEES) by comparing the behavior of proportional valves with HLP and with HEES at various temperatures. The focus of this article is on classic proportional valves used in the industry. The study is based on tests and modelling with characterization of dynamic behavior in mind. The characterization is based on tests of two pressure compensated proportional valves, one with closed loop control of the spool position, and one without. The two ester types tested are one based on a saturated, fully synthetic ester and a regu…
Synthetic Esters in Hydraulic Valves
Each year 35-37 million tons of lubrication is consumed. Hydraulic oils constitute 10.2% of the total lubrication consumption, and a large part of that is lost to leakage, hose burst and accidents. One way of reducing the pollution caused by hydraulic oil lost in nature is to replace the standard mineral oil with an environmentally acceptable oil, EAL. EALs are already being used but to an extent, that is somewhat sector dependant, and reluctance amongst system designers is one of the factors limiting the usage. Hydraulic experts and end-users say, that two of the main obstacles are the lack of knowledge and the fear of technical problems. The objective of this project is to map the current…
CFD Assisted Steady-State Modelling of Restrictive Counterbalance Valves
The counterbalance valve is an important component in many hydraulic applications and its behaviour hugely impacts system stability and performance. Despite that, CBVs are rarely modelled accurately due to the effort required to obtain basic model parameters and the complexity involved in identifying expressions for flow forces and friction. This paper presents a CFD assisted approach to steady-state modelling of CBVs. It is applied to a 3-port restrictive commercially available counterbalance valve. The model obtained is based on detailed measurements of the valve geometry, a single data set and CFD modelling and includes flow forces and friction. The CFD assisted model is compared to expe…
Steady State Counterbalance Valve Modeling with the Influence of Synthetic Ester Oils Using CFD
This study looks in details at the effects of synthetic esters being applied to a counterbalance valve from the perspective of a system engineer. There is limited literature on the subject of applied synthetic esters and as such limited unbiased sources for information. This creates reluctance against the use of these fluids in sectors and regions with no prior experience and knowledge of what to expect. This study expands the applied literature by investigating a commercially available valve using commercial oils, a basic synthetic ester, a fully saturated synthetic ester and a typical mineral oil type for benchmarking. The investigation is based on both computational fluid dynamics and ex…