Hydrostatic equilibrium

About: Hydrostatic equilibrium is a research topic. Over the lifetime, 2451 publications have been published within this topic receiving 62172 citations.

Lattice dynamics of NiTiO3 under high pressure: Raman evidence under two pressure-transmitting mediums

Abstract: Ilmenite-type NiTiO3 has been studied by Raman spectroscopy under hydrostatic and non-hydrostatic pressure. The rhombohedral structure does not undergo phase transitions up to 35 GPa but evidence of it is found under non-hydrostatic pressure at 45 GPa. The pressure evolution of different modes will be discussed in detail. Our findings not only provide direct experimental evidence of difference in the lattice of NiTiO3 between hydrostatic and non-hydrostatic conditions, but also offer a new insight to understand the phase stability region of ilmenite minerals in the deep earth.

Drag Forces Applied on Rock Matrix by Fluid Flow through Fracture Network in Rock Mass

Abstract: It is very important to investigate the forces applied on the rock mass by the fluid flow through fractured rock mass, which is one of the issues for analyzing the stability of rock mass. The forces applied on the fissure walls by the fluid flow include the hydrostatic seepage pressure and the dynamic seepage pressure, i.e., the drag force. Based on the cubic law of the single fissure flow, the equations of the drag forces applied on the fissure walls by the single fissure flow are deduced by means of the momentum law of fluid mechanics. The equations are designated for the cases of no-filled fissure, filled fissure and the combined flow of fluid and the fillings, respectively. The equations have important values for analyzing the effect of fluid flow on the behavior of deformation and strength of fractured rock mass, and are the foundation of the interaction mechanism between stress and fluid flow. Based on the equations, the two kinds of forces applied on the fracture wall of fracture network in rock mass are studied, which include the normal hydrostatic seepage pressure and the tangent drag force. The equivalent node force of joint element is deduced under the two-dimensional and three-dimensional conditions. A numerical computation example is also given to indicate the effect of seepage through fracture network on the stress of rock mass.

Double-pump double-oil-way hydraulic pressure station for ball-disc friction machine

Abstract: A double-pump double-oil-way hydraulic pressure station for a ball-disc friction machine comprises an oil tank, a hydrostatic lubrication system and a hydrostatic loading system The hydrostatic loading system is mainly composed of a filter, a gear pump, a motor, an overflow valve, a one-way valve, a reducing valve, a pressure gauge, a hydrostatic loading system manifold block The hydrostatic lubrication system is mainly composed of a filter, a gear pump, a motor, an overflow valve, a one-way valve, a reducing valve, a pressure gauge, a hydrostatic lubrication system manifold block According to the double-pump double-oil-way hydraulic pressure station for the ball-disc friction machine, two non-interfering hydraulic systems can supply mechanical parts where static pressure shafts work with different working pressure, oil ways are concise and have the advantages of being stable in pressure and accurate in loading, and meanwhile, the oil ways can meet the requirements of different needed rates of flow of the two hydraulic systems, so that the motion stability and the rotation flexibility of the static pressure shafts in the working process of the ball-disc friction machine are guaranteed Therefore, the data collection reliability in a friction test is enhanced, and the friction test precision is enabled to be increased by 10%

Simulating hydrostatic and non-hydrostatic oceanic flows

Abstract: The thin aspect ratio of oceanic basins is simultaneously a complication to contend with when developing ocean models and an opportunity to simplify the equations of motion. Here we discuss these two aspects of this geometric feature in the context of hydrostatic and non-hydrostatic ocean models. A simple analysis shows that the horizontal viscous operator in the hydrostatic primitive equations plays a central role in the specification of boundary conditions on the lateral vertical surfaces bounding the domain. The asymptotic analysis shows that for very thin aspect ratios the leading-order flow cannot be closed unless additional terms in the equations are considered, namely either the horizontal viscous forces or the non-hydrostatic pressure forces. In either case, narrow boundary layers must be resolved in order to close the circulation properly. The computational cost increases substantially when non-hydrostatic effects are taken into account.