In mobile hydraulic systems such as commercial vehicles, hydraulic fluids are splashed and agitated in the reservoirs. To overcome air entrainment in oils, the overall dimensions should enclose a sufficient volume of oil to permit air bubbles to escape passively during the resident time of the fluid in the reservoir. However, in view point of environmental compatibility, energy saving, cost sav...

In a porous material, both the pressure drop across a bubble and its speed are nonlinear functions of the fluid velocity. Nonlinear dynamics of bubbles in turn affect the macroscopic hydraulic conductivity, and thus the fluid velocity. We treat a porous medium as a network of tubes and combine critical path analysis with pore-scale results to predict the effects of bubble dynamics on the macros...

An infinite elastic medium with a planar crack is considered. The crack is subjected to the pressure of fluid injected at a point on the crack surface. Description of the crack growth is based on the lubrication equation (balance of the injected fluid and the crack volume), the equation for crack opening caused by fluid pressure on the crack surface, the Poiseuille equation related local fluid ...

This study presents application of Dynamic Programming towards finding globally optimal control policies of a new, highly-efficient hydraulic elevator architecture. The architecture employs an actuator, three accumulators, and two hydraulic circuits bridged by a hydraulic transformer. An auxiliary electric motor exists only to compensate for system losses. Prior research identified a multitude ...

Pressure pulsation, created by the operation of hydraulic pumps in a fluid power system, is one of the primary causes of noise issues from hydraulic machinery. The wave energy resulting from such pulsation propagates in both the wall and the fluid of the flow pipes associated with the fluid power systems, inducing fluid borne vibration of the pipes and the consequent noise radiated from the pip...

[1] Joint sets within sedimentary basins are commonly interpreted to have formed by tensile failure in conditions where pore fluid pressure was elevated. Such tensile fractures are inferred to be a part of the process that relieves high fluid pressure by locally increasing rock permeability. In spite of the importance of this feedback mechanism, the detailed mechanics of hydraulic fracture gene...

The Hydraulic excavator machines are heavy duty earth mover consisting of a boom, arm and bucket. It works on principle of hydraulic fluid with hydraulic cylinder and hydraulic motors. The Hydraulic excavator backhoe operation require coordinated movement of boom, arm and bucket to control the bucket tip position by following a desired trajectory and to use the excavator machines effectively in...

Modelling fluid flow through fibrous porous materials has gained increasing attention from industry and research communities. The analytical and numerical methods are the two methods commonly adopted to predict the hydraulic characteristics of fibrous material during fluid flow, although to date, most techniques are conducted on the same assumption that the geometric features of fibres remain u...

in this paper, a finite element model is developed for the fully hydro-mechanical analysis of hydraulic fracturing in partially saturated porous media. the model is derived from the framework of generalized biot theory. the fracture propagation is governed by a cohesive fracture model. the flow within the fracture zone is modeled by the lubrication equation. the displacement of solid phase, and...