Hydrostatics buoyancy

Most of the features of the theoretical treatment of bubble motion are present in the treatment that considers the water incompressible and neglects gravity effects. We quote from Cole (Ref 1, Chapt 8) The simplest approximation to the true motion of the bas bubble is the one in which it is assumed that the motion of the surrounding water is entirely radial and there is no vertical migration. In this approximation, which has been discussed by a number of writers, the hydrostatic buoyance resulting from differences in hydrostatic pressure at different depths is neglected. It is thus assumed that at an infinite distance from the bubble in any direction the pressure has the same value as the initial hydrostatic pressure P0 at the depth of the charge... 

The density can also be determined using a "density balance", by measuring the hydrostatic buoyancy of a displacer of known volume. 

This is a convenient point at which to introduce the concept of water in the ground, water table, pressure and pressure measurement and some simple hydrostatics - buoyancy, Archimedes - and ideas of surface tension. This then leads to the logical partition of total stress (which is what we discover that we have been thinking about in applying considerations of equilibrium to the vertical profile of stress in the ground) between pore pressure and effective stress supported by the soil particles. I do not think it is necessary to dwell on putative proofs of the Principle of Effective Stress. It can be treated as a moderately well non-falsified conjecture which has demonstrated its worth over many decades. In early year teaching it is helpful to convey certainties even if we expect to encourage students to query them later on. 

If ship s keel penetrates into the mud layer, the hydrostatic (buoyancy) force acting on the submerged huh increases due to the higher density of the mud. 

More precisely, the apparent density is determined by the hydrostatic (buoyancy) method according to standards ASTM-C-20-00, DIN EN 993-1, and ISO 5017 [16, 25, 26]. The apparent density is calculated according to... 

Consider a form of the vertical momentum equation (Equation (3.24)) term and the pressure as its departure from hydrostatics. In functional with a buoyancy form,... 

The low water absorptivity and good resistance to hydrostatic pressure make syntactic foams very useful for marine and submarine construction. Materials to be used for deep-sea application must have 1) low compressibilities at high hydrostatic pressure, 2) low thermal expansion coefficients, 3) low water absorption, and 4) good fire resistance. The fluids used for buoyancy in deep water submersibles include gasoline, ammonia, and silicone oil, while the solids include plastic, glass and aluminium foams, lithium, wood, and monolithic polyolefins. The liquids are dense but have low... 

Hydrostatic (single-phase fluid) Archimedes buoyancy. Effective stress - established at the boundary. Alters interparticle electrical forces (repulsion, van der Waals attraction, hydration). 

At 0 = 90 degrees, the internal force due to gas pressure is balanced against the hydrostatic pressure of water because the interfacial tension has no component in the direction of the solid surface. In this case, the interfacial tension is directly balanced against the buoyancy of a bubble. Such a direct balance between the interfacial tension and the buoyancy can be justified for only this special case of 0 = 90 degrees. 

MII S-24154A(2) Syntactic Buoyancy Material for High Hydrostatic Pressures, 6 February 1991, 3 pp amend 2 + 17 pp base spec (FSC 9330) (SH)... 

Revision A of this specification was published 10 March 1957. There are two types. Type I for 4,5000 psig hydrostatic pressure and Type II for 10,000 psig. The QPL was cancelled on 31 March 1986. The syntactic buoyancy material consists of a low-density filler such as hollow-glass microspheres in a resin matrix such as epoxy resin. 

These upward directed forces are generally called buoyancy forces and are the driving forces for separate phase oil or gas migration through water under hydrostatic conditions. The magnitude of the buoyancy force for a vertical length Zq of a body of oil or gas immersed in water can be expressed by... 

Hydrostatic secondary hydrocarbon migration systems, in which the dominant forces influencing hydrocarbon migration are the buoyancy forces and the capillary pressure gradients (Section 4.3.3). 

Under hydrostatic conditions, the hydrocarbons will become trapped in the reservoir rock when buoyancy-induced lateral upward hydrocarbon migration in the carrier-reservoir rock is stopped by a capillary pressure boimdary. Hydrostatic trapping positions include structural traps, stratigraphic traps and combination traps. The maximum height of a hydrocarbon column that can be contained in a hydrostatic trap is determined by the sealing capacity and geometry of the rocks, or rocks and faults, that form the trap. 

This buoyancy force consists oftwo distinct contributions fo/fona psg is the gravitational body force on a sphere of density ps, and (4/3)7ra3pg is the net force contribution due to the hydrostatic pressure distribution at the sphere surface. At steady-state, the two forces, (7-169) and (7-170), must balance, that is,... 

We have already noted that the general class of flows driven by buoyancy forces that are created because the density is nonuniform is known as natural convection. If we examine the Boussinesq approximation of the Navier-Stokes equations, (12-170), we can see that there are actually two types of natural convection problems. In the first, we assume that a fluid of ambient temperature 71, is heated at a bounding surface to a higher temperature I. This will produce a nonuniform temperature distribution in the contiguous fluid, and thus a nonuniform density distribution too. Let us suppose that the heated surface is everywhere horizontal. Then there is a steady-state solution of (12-170) with u = 0, and the body-force terms balanced by a modification to the hydrostatic pressure distribution, such that... 

The first term is the pressure at some reference point (xref, yref, zKf) in the ambient fluid far from the body the second term is the hydrostatic pressure of this ambient fluid and the third term, Pd, is the pressure component associated with dynamics of the flow. Substituting Eq. 4.1 for P into the full equations of motion, we find that Pd simply replaces P in the x and y momentum equations. But in the z momentum equation there arises the additional term pM(z)g, representing the hydrostatic pressure gradient force. The local gravitational body force pg also appears in the z momentum equation, and the imbalance between these two forces, represented by the difference p (z)g- pg, is the driving force of natural convection. By introducing P = -(l/p)(dp/d7),> and y= lp(dpldP)r, this imbalance, called the buoyancy force, can be expressed by... 

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