This paper presents a three-dimensional numerical study of the bubble generation process in a micro T-junction, performed with the commercial computational fluid dynamics solver ANSYS Fluent, version 15.0.7. Numerical results on the bubble generation frequency, bubble velocity, volume void fraction, bubble volume, and characteristic bubble lengths are compared with experimental data. Additionally, a new simple fitting for the bubble generation frequency, based upon previously reported experimental works, is proposed here.
A computationally efficient procedure for selection of placement of actuators is described in this paper. This method is formulated in modal coordinates and is based on the so-called progressive collapse analogy of an adjoint structure made of a hypothetical elastic-brittle material and having the same shape as the eigenmodes of the structure to be controlled. The computer simulation of progressive collapse for the adjoint structure provides us (as a side effect) with the location of the most sensitive spots, the best for placement of actuators. The presented methodology can be applied to damping of free vibration as well as to quasistatic shape control problems.