Forced Convection Mass Transfer Inside Large Hemispherical Cavities Under Laminar Flow Conditions

Abstract

Rates of mass transfer at hemispherical cavities machined in the wall of a vertical rectangular duct were measured by an electrochemical technique which involved measuring the limiting current of the cathodic reduction of K 3 Fe(CN), . Variables studied were solution flow rate, physical properties of the solution and cavity diameter. The mass transfer coefficient inside the cavity was found to be less than the flat surfaoe value (the duct wall), and decreased with an increase in the cavity diameter. Mass transfer data inside the cavity were correlated by the equation: ( d )0.33 Sh, = 0.89 SC'Re'w here Sh" and Sc and Re are Sherwood, Schmidt and Reynolds numbers, respectively; and d. and d are the duct equivalent diameter and cavity diameter, respectively. Practical implications of the present results in mass transfer limited processes such as diffusion controlled corrosion, electrochemical machining, electroplating and etching have been highlighted.

Natural convection of melted core at the bottom of nuclear reactor vessel in a severe accident

“…Levich and Agar first proposed this system to investigate the heat transfer, and Selman and Tobias developed the method further. Zaki et al reported the use of mass transfer experiments. Chung et al have also published a series of experimental results applying the methodology for various flow conditions and geometries.…”

“…and Agar 19 first proposed this system to investigate the heat transfer, and Selman and Tobias 20 developed the method further. Zaki et al21 …”