Mark M. Weislogel

Capillary-driven flows along rounded interior corners

The problem of low-gravity isothermal capillary flow along interior corners that are rounded is revisited analytically in this work. By careful selection of geometric length scales and through the introduction of a new geometric scaling parameter

Some analytical tools for fluids management in space: Isothermal capillary flows along interior corners

overline T_c

Capillary flow in interior corners: The infinite column

, the Navier–Stokes equation is reduced to a convenient

Gravity Effects on Capillary Flows in Sharp Corners

,{sim}, O(1)

Capillary driven flow along interior corners formed by planar walls of varying wettability

form for both analytic and numeric solutions for all values of corner half-angle

A better nondimensionalization scheme for slender laminar flows: The Laplacian operator scaling method

alpha

The Shape and Stability of Wall-Bound and Wall-Edge-Bound Drops and Bubbles

and corner roundedness ratio

Capillary Driven Flows in Weakly 3 -Dimensional Polygonal Containers

lambda

THE CAPILLARY FLOW EXPERIMENTS: HANDHELD FLUIDS EXPERIMENTS FOR INTERNATIONAL SPACE STATION

for perfectly wetting fluids. The scaling and analysis of the problem captures much of the intricate geometric dependence of the viscous resistance and significantly reduces the reliance on numerical data compared with several previous solution methods and the numerous subsequent studies that cite them. In general, three asymptotic regimes may be identified from the large second-order nonlinear evolution equation: (I) the ‘sharp-corner’ regime, (II) the narrow-corner ‘rectangular section’ regime, and (III) the ‘thin film’ regime. Flows are observed to undergo transition between regimes, or they may exist essentially in a single regime depending on the system. Perhaps surprisingly, for the case of imbibition in tubes or pores with rounded interior corners similarity solutions are possible to the full equation, which is readily solved numerically. Approximate analytical solutions are also possible under the constraints of the three regimes, which are clearly identified. The general analysis enables analytic solutions to many rounded-corner flows, and example solutions for steady flows, perturbed infinite columns, and imbibing flows over initially dry and prewetted surfaces are provided.

A High Performance Semi-Passive Cooling System: The Pulse Thermal Loop

Abstract Recent advances in the analysis of a class of capillary-driven flows relevant to materials processing and general fluids management in space have been made. The class of flows addressed concern spontaneous capillary flows in complex containers with interior comers. Such flows are commonplace in space-based fluid systems and arise from the particular container geometry and wetting properties of the system. Important applications for this work involve low-g liquid fill and drain operations where the container geometry is complex, possessing interior corners, and where quantitative information of fluid location, transients, flow rates, and stability is critical. Examples include the storage and handling of liquid propellants and cryogens, water conditioning for life support, fluid phase-change thermal systems for temperature control and power production, materials processing in the liquid state, and on-orbit biofluids processing. For several important problems, closed-form expressions to transient three-dimensional flows are possible that, as design tools, compliment if not replace difficult, time-consuming, and rarely performed numerical calculations. The theory is readily extended to address more complex flows. An overview of a selection of solutions in-hand is presented. Drop tower and low-g aircraft experimental results are cited to support the theoretical findings.