Showing papers on "Shell balance published in 1964"

Fluid Mechanical Aspects of Antisymmetric Stress

Abstract: Basic fluid mechanical concepts are reformulated in order to account for some structural aspects of fluid flow. A continuous spin field is assigned to the rotation or spin of molecular subunits. The interaction of internal spin with fluid flow is described by antisymmetric stress while couple stress accounts for viscous transport of internal angular momentum. With constitutive relations appropriate to a linear, isotropic fluid we obtain generalized Navier‐Stokes equations for the velocity and spin fields. Physical arguments are advanced in support of several alternative boundary conditions for the spin field. From this mathematical apparatus we obtain formulas that explicitly exhibit the effects of molecular structure upon fluid flow. The interactions of polar fluids with electric fields are described by a body‐torque density. The special case of a rapidly rotating electric field is examined in detail and the induction of fluid flow discussed. The effect of a rotating electric field upon an ionic solution is analyzed in terms of microscopically orbiting ions. This model demonstrates how antisymmetric stress and body torque can arise in ``structureless'' fluids.

Fluid Behavior in Zero Gravity

Abstract: The handling of fluids in the absence of gravity presents many problems. In this paper consideration is given to the zero-gravity spatial configuration of a wall wetting (zero contact angle) fluid which has given surface interface energy relationships (YSY ≥ YLS + YLV). For this model, which probably is correct for cryogenic fluids and stainless steel tanks, equilibrium predictions are made as follows: 1) The fluid will wet the tank wall and distribute itself so as to forma vapor space in the central portion of the tank. 2) The vapor space will be a sphere if a spherical shape can accommodate the volume of vapor present. 3) If too much vapor is present to be accommodated by a sphere, then a configuration will result such that surfaces backed by bulk liquid are of uniform curvature and other surfaces will be filmwetted tank walls. 4) The thickness of the film, on the “film-wetted” walls, will be of the order of a few hundred mμ under isothermal conditions. 5) The curvature of the bulk liquid surfaces will be uniform and will be greater than or equal to the curvature of any exposed film wet surface. 6) Tubes of diameter smaller than the tank diameter will fill with fluid. 7) There are shapes of baffles, etc. , which will act as a “wick” and cause the fluid to collect in a desired volume.