In this paper, we present an algorithm which can automatically recognize vapor bubbles in a seething liquid from an image sequence. The image sequences were taken with a high-speed video camera with one thousand images pro-second. Our algorithm was divided into two steps: the background image identification and the bubble recognition. In the first step, the technique for auto-focus was applied ...

The complex dynamics of a single bubble of a few millimeters in size oscillating inside a narrow fluid-filled gap between two parallel plates is studied using high-speed videography. Two synchronized high-speed cameras were used to observe both the side and front views of the bubble. The front-view images show bubble expansion and collapse with the formation of concentric dark and bright rings....

We report an experimental study of bubble dynamics in a non-Newtonian fluid subjected to a pressure decrease. The fluid is a hydrogel, composed of water and a synthetic clay, prepared and sandwiched between two glass plates in a Hele-Shaw geometry. The rheological properties of the material can be tuned by the clay concentration. As the imposed pressure decreases, the gas initially dissolved in...

Digital Image Analysis (DIA) has been employed to characterize the time evolution of a bubble injected from a single orifice into a pseudo 2-dimansional gas-solid fluidized bed. The injected bubble diameter increased with the square root of time before detachment. During bubble free flight in the bed, its diameter remains approximately constant. The center of mass of the bubble increases with t...

The generic square-gradient density-functional model with triple-parabolic free energy is used to study the stability of a cavity introduced into the stretched liquid. The various properties of the critical cavity, which is the largest stable cavity within the liquid, are compared with those of the critical bubble of the homogeneous bubble nucleation. It is found that the size of the critical c...

separation method that is widely used in coal beneficiation for the separation of fine coal particles from associated minerals in water slurries. Since the cumulative recovery of a component in the concentrate is proportional to flotation time, the flotation process can be considered as a time-rate recovery process (Emad, Mohammad, and Bahram, 2010). Therefore, the general mathematical flotatio...