A fluid is a substance in which the constituent molecules are free to move relative to each other Conversely, in a solid, the relative positions of molecules remain essentially fixed under non-destructive conditions of temperature and pressure While these definitions classify matter into fluids and solids, the fluids subdivide further into liquid and gases

Introduction of fluid mechanics

We present solutions for nutrient transfer to osmotrophs in the full range of flow regimes for which solutions have been published, and we extend some of those solutions to new parameter domains and flow environments. These regimes include stagnant water; steady, unitorm flow arising from swimming or sinking; steady shear flows; and fluctuating shear from dissipation of turbulence, as well as the combined effects of turbulence-induced shear and swimming or sinking. Solutions for nutrient fluxes cannot be carried over from one flow regime to another. In all cases, however, mass transfer increases with cell size and with flow velocity. Cell shape becomes particularly important at high flow velocities. For steady, uniform flow arising from sinking or swimming, we find asymptotic analytic and numerical solutions from the engineering literature superior to those in more common use within oceanography. These engineering solutions suggest flow effects an order of magnitude smaller than commonly supposed. A cell radius near 20 Ilm is needed before swimming or sinking can be expected to increase the flux of nutrients, such as nitrate or phosphate, substantially (by ~50%) over the stagnant-water case. We find sound asymptotic solutions for the case oflinear shear and supplement them with numerical solutions of our own to cover the range of cell sizes and shear rates of interest for phytoplankton. We extend them further to cover viscous shears from dissipating turbulence for cells smaller than the Kolmogorov scale (order of 1-6mm in the ocean). Our analysis suggests turbulence effects an order of magnitude greater than previously postulated, with a cell size of 60~lm needed to experience substantial gain. Cell rotation, whether induced by the propulsion mechanism in swimming or passively by shear across the cell perimeter, will reduce the rate of nutrient transfer relative to a non-rotating cell unless the axis of rotation parallels the direction of flow. Although in calm water dinoflagellates by swimming are able to increase nutrient uptake, in strong turbulence they may not be able to maintain a rotational axis parallel to the direction of swimming or the direction of shear, resulting in a relative reduction in flux. Conversely, large chains of diatoms and filamentous cyanobacteria that span the radius of the smallest vortices are best able to take advantage of turbulence. Despite these deductions from a diversity of analytic and numerical solutions, unequivocal data to test the contribution of advection to nutrient acquisition by phytoplankton are scarce owing, in large part, to the inability to visualize, record and thus mimic fluid motions in the vicinities of cells in natural flows.

http://misclab.umeoce.maine.edu/documents/karpbossetal_1996.pdf

Patterns in the ocean: Ocean processes and marine population dynamics

While the chemical aspects of igneous petrology have dominated research for many years, the physical processes associated with the generation, transport, and crystallization of magma have been somewhat neglected. Here a group of distinguished scientists, whose current research embraces both chemical and physical aspects of the field, illustrates these new directions in igneous petrology. Originally published in 1980. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These paperback editions preserve the original texts of these important books while presenting them in durable paperback editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.

/pdf/physics-of-magmatic-processes-4b82qquj87.pdf

Physics of Magmatic Processes

An investigation of heat transfer and friction for rib-roughened surfaces

This review is devoted to the introduction of second-law analysis in heat transfer and entropy generation minimization in thermal design. The presentation proceeds from the derivation of the Gouy-Stodola theorem, the basis for entropy generation minimization in the conceptual design of heat transfer equipment. Appropriate analytical tools, such as the entropy generation number, are devised for the task of estimating the destruction of available work in the processes involving heat transfer. However, the entropy generation number concept is considerably more general, since it can be used to quantitatively describe the degree of irreversibility of engineering components and processes which do not draw their irreversibility solely from heat transfer. The examples considered in this article range from the irreversibility associated with some of the most fundamental convective heat transfer processes to the minimum irreversibility design of one-dimensional insulations such as the main counterflow heat exchanger of a helium liquefaction plant.

Warren M. Rohsenow

Papers

Heat Mass and Momentum Transfer