Investigation of the Effects of Capillary Grooves on Surface Wetting and Evaporation.

摘要

The static and dynamic rise of a liquid phase was examined experimentally and theoretically in capillary grooves of square,semicircular and triangular cross sections. In static equilibrium,the wetting characteristics are described in terms of a 'fully-wetted'height which can be predicted for given physical properties from an 'equivalent capillary radius.''Results of experimental measurements and numerical computations are in fair agreement with the proposed prediction method. For the dynamic rise,an attempt was made to obtain expressions which approximately predict heat-transfer rates in order to select for given properties and temperature differences a groove of optimum design. Liquid flow rates in capillary grooves were measured by means of a forced-convection mass-transfer equipment based on the wetted-wall column principle. The results are studied for agreement with predictions computed for evaporation heat-transfer and related to mass-transfer by using Reynolds analogy for pipe flow. (Author)