Hydrostatic equilibrium

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

Necessity of Hydrostatic Stability in Autonomous Underwater Vehicles on Intervention Missions

Abstract: Most underwater vehicles are hydrostatically stable, i.e., their center of gravity is placed below their center of buoyancy, providing passive stability in pitch and roll. While this design is favorable for fixed attitude missions, it is a hindrance for tasks requiring flexible orientation control. This work examines the influence of hydrostatics on attitude control of a fully actuated intervention type Autonomous Underwater Vehicle (AUV). We conducted a simulation study varying influencing factors, such as hydrostatic stability, thruster dynamics, disturbance, and controller choice. We found that the impact of hydrostatic stability on control performance and energy consumption is drastically reduced, if thrusters with sufficiently high dynamic range are used. Our results support the concept of intervention AUVs, which are highly agile through marginally stable design.

Dynamics of the distribution of the main parameters of the magma melt in the volcano slot cross section under instantaneous decompression

Abstract: The dynamic behavior of the magma melt saturated with a strongly compressed gas at a high temperature, which is located between two rigid boundaries aligned symmetrically with respect to the vertical axis, is considered. A constant pressure is maintained at the channel bottom, while the pressure in the medium is initially distributed in accordance with the hydrostatic law. The top of the channel is hermetically sealed with a plug, which is affected by a constant pressure equal to the atmospheric value. The state of the melt after instantaneous removal of the plug is studied.

The study of pressure source term in moving particle semi-implicit (MPS)

Abstract: In this paper pressure source terms proposed by different researcher are compared in term of pressure stability. In Moving Particle Semi-Implicit (MPS) method, the pressure error is compensated back into pressure Poisson equation as source term in order to enforce the incompressibility. However the non physical pressure fluctuation still remains an open problem in MPS method. In present study the hydrostatic model is used as example to study the pressure stability for each of the pressure source terms. The pressure at the fixed point over time is plotted and the fluctuation from the theoretical pressure is discussed.

Master's thesis: On the investigation of dark matter haloes

Abstract: In this thesis I will show that it is possible to 1) derive all the physical properties of the gas in clusters of galaxies from the dark matter distribution alone, and 2) that it is possible to use this to determine the dark matter density profile from the surface brightness alone. When the dark matter density profile is known, then other radial profiles of the gas properties, such as temperature or density, can be computed and compared to observations to check if the result is consistent with the assumptions. Besides assuming the validity of the Jeans equation and hydrostatic equilibrium we also assume that there is a linear relation between the density slope and anisotropy (γ ∼ β relation) and a constant relation between the dispersions of the dark matter and the gas (the dark matter temperature relation) which both have been confirmed through numerical simulations.

Assessment of Collapse Pressure of Laminated Composite Subsea Shells Subjected to Hydrostatic Follower Force

Abstract: A doubly curved composite shear deformable shell element has been developed for the buckling analysis of composite subsea shells which takes into consideration the effect of hydrostatic follower force. This element is based on first-order shear deformation theory considering the nonlinear curvature terms of the strain–displacement relations in order to simulate the realistic structural behaviour of thin composite shells. It has been employed for the prediction of collapse pressure, including the follower force effect of thin composite cylindrical and shallow shell panels, which form a part of subsea structures.