ABSTRACT
Recently microbubble has gained a lot of attention. Microbubbles are the bubbles having diameter in the order of 50 µm. They possess a lot of spectacular properties which makes them superior over the conventional bubbles. According to Young-Laplace equation the excess pressure inside a bubble is inversely proportional to its size [1]. The internal pressure depends on the intermolecular and molecule-wall interactions. If the diameter of the bubble increases, the intermolecular interaction and the molecule-surface interaction decrease whereas it increases as the size of the bubble decreases. The microbubble, due to their small size exhibit high pressure and thus provides a high gas dissolution rate. They are also beneficial as they provide large gas liquid interfacial area. They experience a low degree of buoyance force, due to their small size, which gives them a long residence time in the liquid as compared to micro-and macrobubbles. They find a large number of applications in engineering as well as medical field. Microbubbles can increase the efficiency of gas-liquid contacting devices for various applications in chemical, petrochemical, and biochemical processes [2-5]. Despite of such extreme uses, the flow behavior of microbubble-liquid mixture has not been analyzed properly. During the simultaneous flow of microbubble-liquid mixture through a device, various hydrodynamic characteristics such flow behavior, pressure drop, friction factor, interfacial stress have to be analyzed. In the present chapter the rheological behavior and friction factor of microbubble-liquid mixture is studied in pipe.
