Enhancing Bubble Behavior on Heated Surface with External Flow using Volume of Fluid Model

Abstract

In this study, we researched augmenting bubble behavior on heat with external flow using volume of fluid model. The subject is also concerned about the implementation methodology of heat transfer enhancement in nuclear power plants . The main objective of this research is to show how force convection heat transfer can be augmented in nuclear power plants by means of a certain structure that can push hot liquids or bubbles out of neighboring heated surface. We carried out numerical experiments in this regard considering theoretical backgrounds and result have been elucidated in the subsequent sections. When an intricate piece of machinery of reactor core (or U-shaped heat exchanger) is taken into consideration, it is observed that an artificial flow of fluid is generated by an impeller or outlets of induction pipes that cannot be embodied easily in case of fission reactors, although it can be easily figured out in case of tokamaks. The main goal of this study is how to use force convection for nuclear plants with a certain device and design plan. For example, in nuclear power plant, a structure which can push hot liquid or bubbles out of neighboring area of heated surface for force convection was bodied out. When an intricate piece of machinery of reactor core (/or U-shaped heat exchanger) is taken into consideration, it seems that an artificial flow of fluid which is produced from an impeller or outlets of induction pipes cannot be bodied out easily. But an artificial flow of fluid which is produced from an impeller or outlets of induction pipes can be bodied out even in tokamaks. In the case of structures which produce forced convection or bubble pushing, the volume of provided cooled liquid or the speed of departure of bubble on the surface of heated surface is expected to be in proportion to speed of moving structure, moving liquid or the effect of shape of volume. Apart from that numerical study of the movement of bubble is performed using the Volume of Fluid (VOF) model of commercial CFD software named ANSYS. The modeling of force convection heat transfer in order to increase the departure of iv bubble is performed. Also, the behavior of the bubble which is elicited by the different type of force convention is investigated with expectation of effectiveness for heat transfer enhancement in nuclear plants. As a method of enhanced heat transfer, this paper focused on the characteristics of convective heat transfer by using forced artificial flow which connected with motor or pump or outer force such as flow of fluid. A bubble cutter system has been used as the passive heat exchanger in this study. In addition, an artificial flow system that can cut (and/or push and break) bubbles is explained to drag bubbles. The rate of convective heat transfer will be increased by the local forced convection. In this study, different types of artificial flow have been examined by comparing results with VOF modeling. The departure of bubble can be accelerated by the artificial flow which in turn will increase heat transfer. The qualitative features of the bubble departure have been shown by numerical simulation.