Mixed time–frequency domain simulation of a hydraulic inductance pipe with a check valve

Abstract

This paper deals with the efficient computation of hydraulic switching systems with a check valve by a mixed time–frequency domain method; frequency-domain modelling is performed on the wave propagation in a pipe and time-domain modelling is applied to the switching valve and the check valve. The dual property of the check valve makes the complete problem have variational inequality properties. A solution method is presented which replaces the pressure and the flowrate of the check valve as a function of one new variable. The resulting system of non-linear algebraic equations is solved using a Newton–Raphson method in combination with a smoothing of the non-smooth properties of the check valve. The method is applied to a parameter study of a hydraulic buck converter.

Multifunctional four-port directional control valve constructed from logic valves

“…Besides, the flow curves were obtained, which confirmed the results from the CFD analysis. In addition, if we compare features such as: internal leak tightness, and the maximum switching frequency [13,14], the use of logic valve, despite its more complex design, may be significantly beneficial for many hydraulic systems.…”

“…The development of those creates the possibility of higher internal tightness and greater speed of control, and the ability to build special systems for large capacities of the volumetric flow rate, even several thousand liters per minute [11][12][13][14]. The logic valves are relatively new solutions, which are being systematically introduced to hydraulic controls and drives.…”

Theoretical and Experimental Studies of a Switched Inertance Hydraulic System in a Four-Port High-Speed Switching Valve Configuration

“…The HBC has been successfully applied in robots and agricultural machines [11,12]. The mixed time-frequency domain model of a hydraulic inductance pipe with a check valve is proposed by Scheidl and Manhartsgruber [13]. The time-domain modelling was applied to the switching valve and the check valve, while the frequencydomain modelling was used to model the wave propagation in a pipe.…”

Theoretical and Experimental Studies of a Switched Inertance Hydraulic System in a Four-Port High-Speed Switching Valve Configuration  

“…The HBC has been successfully applied in robots and agricultural machines [11,12]. The mixed time-frequency domain model of a hydraulic inductance pipe with a check valve is proposed by Scheidl and Manhartsgruber [13]. The timedomain modelling was applied to the switching valve and the check valve, while the frequencydomain modelling was used to model the wave propagation in a pipe.…”