This paper presents a comparison between measured and predicted results of the in-cylinder tumble flow and the flow coefficient generated by a port-valve-liner assembly on a steady-flow test bench. In this study, computational fluid dynamics (CFD) methods were employed to gain further insight into characteristics of an engine. The purpose was to advance understanding of the stationary turbulenc...

In the paper a comprehensive model of a piston ring pack motion on an oil film has been presented. The local oil film thickness can be compared to height of the combined roughness of sliding surfaces of piston rings and cylinder liner. Equations describing the mixed lubrication problem based on the empirical mathematical model formulated in works of Patir, Cheng and Greenwood, Tripp have been c...

Reciprocating compressors are most common type of compressor and most flexible machine to handle wide capacity and condition swings. They offer a most efficient method of gas compressing. They are vital machines in various units of industrial plants. In this paper advanced technologies and latest configurations and methods regarding condition monitoring, performance, flow management, capacity c...

A bstractThis paper presents a feedback linearisation approach to the control of electrohydraulicservo systems of a robotic excavator. The control system of the bucket hydraulic cylinder is used as a testbed. Simulation and experimental results are provided. The results obtained demonstrate the advantage of the proposed controller over conventional linearised controllers in dealing with nonline...

Hydraulic actuator has been widely used in industrial applications due to its fast response and capability of moving heavy load. The nonlinear properties of hydraulic cylinder had challenged researchers to design a suitable controller for position control, motion control and tracking control. Based on these problems, we had done a real-time digital tracking control studies on electrohydraulic c...

The aim of this paper is to analyze the driving system actuated by a proportional directional control valve on a hydraulic cylinder. In order to evaluate the dynamic interaction between the proportional valve and the cylinder theoretical analysis, numerical simulations as well as experimental test are performed. Coupling cylinder and proportional valve, it is very important to know the ratio of...

The present hydraulic variable-pitch mechanism of wind turbine uses three hydraulic cylinders to drive three crank and connecting rod mechanisms respectively; the blades are moved with the cranks. The hydraulic variable-pitch mechanism has complex structure, occupies a lot of space and its maintenance is trouble. In order to make up for the shortcomings of hydraulic cylinder variable-pitch syst...

In the liner-ejecta experiments carried out at the Los Alamos pulsed power facility Pegasus II, a solid liner was magnetically imploded to impact on a target cylinder to produce the shockinduced ejecta. As a result of improved time resolution for the B-dot (dB/dt) probes fielded last fall, we began to notice a sharp jump in the B-dot curve occurring at a time very close to the expected liner-ta...

The internal cushioning systems of hydraulic linear actuators avoid mechanical shocks at the end their stroke. design where piston with perimeter grooves regulates flow by standing in front outlet port has been investigated. First, a bond graph dynamic model developed, including throughout cushion design, characterized detail computational fluid-dynamic simulation. Following this, radial moveme...

A monopropellant powered free piston hydraulic pump (FPHP) was designed as a human scale (1.0 to 3.0 kW) mobile robotics power supply. The FPHP utilized high concentration hydrogen peroxide, which decomposes into hot gas when exposed to a catalyst, as the monopropellant energy source. Energy was extracted from the hydrogen peroxide and transferred directly to hydraulic fluid by expanding the ho...