Wet chemical ethching is used for making microscopical products like lead frames, printed wiring boards, shadow masks and so on. We investigate numerically fluid dynamical aspects and mass transport phenomena nearby the etching cavity, using a standard two dimensional MAC method. Etching is assumed to be limited by removal of the dissolution products away from the vicinity of the active suface. In addition, the shape evolution of etching cavity is computed in a quasistationary manner.
Flow velocity distributions in a central vertical plane associated with the negatively buoyant gravity jet discharged into a homogeneous or linearly stratified fluid have been measured using a two-dimensional PTV, which is based on the newly developed super-resolution KC method1). The method has turned out to be useful in clarifying the detailed inside structure of the gravity jets. The gravity jet discharged into a stratified fluid has been found to exhibit a wavy pattern as it is mixed with the surrounding fluid.