| Summary: | ABSTRACT
The motion and spreading of air bubble highly affect the effectiveness and efficiency of aeration process. This research developed a numerical model to simulate and to predict the motion and the spreading of air bubble in an aerator column. In this approach, modeling of aeration process considers air bubbles as a material that transported and dispersed in the water. The model assumed that bubble diameter could be ranged in their size. The dynamics of air bubbles motion and spreading is modeled as convection-diffusion equation and implemented only for one diameter range. Petrov-Galerkin Finite Element Method on 20 nodes quadratic brick element is used to solve this equation. To develop the model, velocity and diffusion coefficient was determined based on the results of the investigation of air bubble motion and spreading in the column aerator. From the modeling results of the motion and spreading of air bubble, the relation between diffusion coefficient and the air bubble concentration with 2 It/mnt sparger discharge was found, k=0,12(C-0,0006), where k is diffusion coefficient and C is air bubble concentration. To show the performance of the model, a comparison to the result of the air bubble motion investigation was carried out. The numerical model that has been obtained is capable in simulating the phenomenon of the dynamics of air bubble motion and spreading.
Keywords : Air Bubble Spreading, Convection-Diffusion, and Finite Element Method.
|
|---|