Gravity fluid dynamics

Todd P (1990) In Roster JN, Sani RL (eds) Progress in astronautics and aeronautics progress in low-gravity fluid dynamics and transport phenomena. AlAA, Washington, vol 130, p 539... 

Antar, B. N. Nuotio-Antar, V. S. 1993. Fundamentals of Low Gravity Fluid Dynamics and Heat Transfer. CRC Pre.ss Boca Raton, Fla. 

Shkadov, V. Y. (1967). Wave flow regimes of a thin layer of viscous fluid subject to gravity. Fluid Dynamics 1 43-51. 

Todd, P. In Progress in Low-Gravity Fluid Dynamics and Transport Phenomena. Koster, J. N. Sani, R. L., Eds. Progress in Astronautics and Aeronautics vol. 130, American Institute of Aeronautics and Astronautics, Washington, DC, 1990 pp. 539-602. 

After a fragment has attained a certain initial velocity, the forces acting upon it during flight are those of gravity and fluid dynamics. Fluid-dynamic forces are subdivided into drag and lift components. The effects of these forces depend on the fragment s shape and direction of motion relative to the wind. 

The presence of a lithosphere with a thickness up to 100 km above the plume head obscures observations that could be made in terms of heat flow, gravity field or seismic structure. Establishing the temperature and flow fields beneath a hotspot thus becomes a difficult exercise. Several key parameters (Fig. 2) are poorly constrained and mostly result from theoretical fluid dynamics model, which underlines their large uncertainty. The temperature anomaly within the hotspot region is generally estimated to be approximately 200 100°C with large uncertainties (Shilling 1991 Sleep 1990). These temperature anomalies will induce smaller densities in the plume and the flux of the density anomalies is called buoyancy flux as defined in (Sleep 1990) ... 

Figure 14a, compared with the stable equilibrium bubble shape (Figure 14b) or the stable droplet shape during the evaporation stage in (Figure 4a). Thus the initial flux of CO2 into ethanol at P < Pm is much faster than the reverse process of ethanol evaporation, which can be explained by the higher equilibrium concentration of CO2 in the ethanol-rich phase and also by the larger coefficient of internal mass transfer in comparison to the vapor phase. Clearly, fluid dynamics plays a very important role for both internal and external mass transfer, as illustrated by the very strong gravity convection (concentration plumes) clearly visible in Figures 4 and 14a.

In fluid dynamics this is known as the equation of motion and applies to all types of fluids in motion or at rest. The only restriction is that gravity represents the external force field for hydrodynamics or hydrostatics. The hydrostatic equation (i.e., Vp = pg) is obtained by ignoring all terms that contain v and t. Each term has units of force per unit volume. 

Viscosity of Newtonian liquids ean be measured by calibrated glass capillary viscometer. Kinematic (the resistance to flow of a fluid under gravity) and dynamic (the ratio between the applied shear stress and the rate of shear of a liqitid) viscosities can be calculated from measured time of flow using the following equations ... 

In fluid dynamics fluids are in motion. Generally, they are moved from place to place by means of mechanical devices such as pumps or blowers, by gravity head, or by pressure, and flow through systems of piping and/or process equipment. The first step in the solution of flow problems is generally to apply the principles of the conservation of mass to the whole system or to any part of the system. First, we will consider an elementary balance on a simple geometry, and later we shall derive the general mass-balance equation. 

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