Laminer Filmy Condensation on Vertical Grooved Surfaces

Patterning flows using grooved surfaces.

Through a simple analytical description we quantify how pressure-driven flows over grooved surfaces develop transverse components, which, for shallow grooves, can be modeled with simple anisotropic effective boundary conditions. Helical recirculation results in channels or capillaries with grooved walls. An experimental validation of our model is presented. Our analysis provides a workable guid...

Analysis of Laminar Film Condensation on a Vertical Plate

Tailoring anisotropic wetting properties on submicrometer-scale periodic grooved surfaces.

The use of simple plasma treatments and polymer deposition to tailor the anisotropic wetting properties of one-dimensional (1D) submicrometer-scale grooved surfaces, fabricated using interferometric lithography in photoresist polymer films, is reported. Strongly anisotropic wetting phenomena are observed for as-prepared 1D grooved surfaces for both positive and negative photoresists. Low-pressu...

Film condensation on non-isothermal vertical plates

An analytical study is presented of the condensation of a pure saturated vapour on a cooled channel plate, including the interaction between the cooling liquid, the condensate and the vapour. The governing equations of co-, counterand cross-current condensation are derived, set dimensionless and solved in closed form. The resulting implicit expressions are evaluated numerically by iteration. In...

Experimental Studies on Grooved Surfaces to Suppress Secondary Electron Emission

Grooved surfaces are effective to suppress the secondary electron emission, and can be a promising technique to mitigate the electron cloud effect in positron/proton storage rings. Aiming for the application in a dipole-type magnetic field, various shapes of triangular grooved surfaces have been studied at KEK. The grooves tested here have vertex angles of 20−30°, depths of 2.5−5.0 mm, and vert...