Bubble Production And Its Dynamic Characteristics In Micro-channel

In the micro mechanical system, bubble, as a kind of potential power, plays an important role. With respect to devices and working environment, we need the different bubbles. As the change of bubble is reflected by CCD or the dynamic characteristics, the research on the dynamic characteristics of bubble in micro-channel, is necessary for the choose of micro mechanical system, and deciding its working condition.Firstly, to achieve the goal of making the bubble collapse at the fix-point in micro-channel, we design and product a micro fluidic chip with a wavy groove on it.Secondly, we study the collapsing process of bubbles in freedom and micro-channel respectively by molecular dynamic simulation. We obtain the characteristics of the different bubbles during the collapsing process by analyzing the dynamic characteristics such as potential energy and pressure. The results show that the collapsing progress of bubbles lying in free space includes expanding and shrinking, but the collapsing progress of bubbles in micro-channel includes shrinking only. We also discuss the change of dynamic characteristics of bubbles with respect to the temperature and density. The higher temperature or lager density will accelerate collapsing speed.Then, we study the production of bubble in different angles by using the numerical simulation. Also, we talk about the effects of liquid velocity and the pin-hole’s diameter on departed time and departed radius. The results indicate that bubbles’departed time and departed radius will reduce as the increasing of liquid velocity, but will increase as the increasing of the pin-hole’s diameter. We can get a smaller bubble with the pin perpendicular to the direction of liquid velocity.Lastly, we care about the profile of bubble in micro-channel in the way of numerical simulation. The simulation result shows that the bubble could collapse at the forecasted point as we design. And we discuss the effect of fluidic velocity, geometry of micro-channel and bubble’s size on the collapsing point.