1 Abstract The paper presents a hydraulic astable multivibrator system. The system consists of hydraulic resistors, hydraulic capacitors and hydraulic pressure controlled valves. The system is designed, realised and tested. The measured system behaviour agrees well with the model simulations. The free running frequency of the multivibrator is 0.18 Hz and the output pressure swing is 90% of the ...

Hydraulic excavator energy saving is important to relieve source shortage and protect environment. This paper mainly discusses the energy saving for the hybrid hydraulic excavator. By analyzing the excess energy of three hydraulic cylinders in the conventional hydraulic excavator, a new boom potential energy recovery system is proposed. The mathematical models of the main components including b...

We analyze the motion of viscous and incompressible liquids in the annular space of controllable hydraulic resistances with a cylindrical linear slide-valve. This theoretical study focuses on the turbulent and steady-state motion regimes. The hydraulic resistances mentioned above are the most frequent type of hydraulic resistances used in hydraulic actuators and automation systems. To study the...

INTRODUCTION ................................................................................ 882 I. HYRAULIC FRACTURING POSES ENVIRONMENTAL RISKS TO DRINKING WATER SUPPLIES ........................... 885 II. HYDRAULIC FRACTURING REGULATION IN THE UNITED STATES ..................................................................... 887 A. THE SAFE DRINKING WATER ACT AND THE EPA’S TIMID IMPLEMENT...

This paper describes the implementation of a real-time hydraulic model of a water distribution system in Singapore. This on-line system is based on the Integration of real-time hydraulic data with hydraulic computer simulation models and statistical prediction tools. To facilitate this implementation, a network of wireless sensor nodes continuously sample hydraulic data such as pressure and flo...

in order to comply with stringent pollutant emissions regulations, a detailed analysis of the engine combustion and emission is required. in this field, computational tools like cfd and engine cycle simulation play a fundamental role. therefore, the goal of the present work is to simulate a high speed di diesel engine and study the combustion and major diesel engine emissions with more details,...

In order to study the numerical control (NC) servo press hydraulic control system and its control algorithm. The numerical control servo press performance and control principle of hydraulic control system are analyzed. According to the flow equation of the hydraulic control valve, hydraulic cylinder flow continuity equation and the force balance equation of the hydraulic cylinder with load pres...

Abstract In general two basic methods are used for controlling the velocity of a hydraulic cylinder. First by an axial variable-displacement pump for controls flow to the cylinder. This configuration is commonly known as a hydrostatic transmission. Second by proportional valve powered by a constant-pressure source, such as a pressure compensated pump, drives the hydraulic cylinder. In this stud...

1 Hans Kleine Büning, Benno Stein ABSTRACT Configuration is a process of creating complex systems out of a finite set of predefined objects. This process may enclose the selection, the assemblage and the adaptation of these objects. In this paper we want to describe how the configuration of hydraulic plants can be supported. A hydraulic plant is a complex system that consists of electronic, mec...

Editorial Board Eric Britton, Managing Director, EcoPlan International, The Centre for Technology & Systems Stud ies, 10 rue Joseph Bara, 75006 Paris, France. Paul Tra nter , Senior Lecturer, School of Geography & Oceanography, Un iversity College, Australian Defence Force Academy, Canberra ACT 2600, Australia. John Ho we, Professor of Transportation En gineering & Head of Infrastructural En gi...