摘要或動機

本研究目的在探索不同大小之氣泡在不同黏滯性液體中運動情形。實驗結果發現大氣泡向上運動的速度較大，其下方會漸漸向內凹。並且觀察到氣泡間結合時的相互作用：氣泡在相同黏滯性膠水中上升時，若下方氣泡體積較大，其較快的速率會使距離縮短。此時小氣泡的下半向內凹，大氣泡的下半則向外呈現流線型尖端並且在接近小氣泡時速率增加，最後與小氣泡結合。若上方氣泡體積很小，與下方大氣泡的距離縮短至相互貼合，小氣泡會先停留在大氣泡的上半表面，再沿大氣泡表面下滑至大氣泡的下半才與大氣泡結合。This research traces the motions of bubble with different volume in viscid liquid. The experimental results show that the bigger bubble rises at faster speed. The shape of the small bubble is round. As the volume of the bubble increases, it turns hamburger-like. And if the bubble is big enough, its underside would be concaved. In viscid liquid, the speed of the bubble is not smooth but waved. The smaller the bubble is, the more the variation in speed is. The interaction of two bubbles is also studied. There are two types of the combination of two bubbles. While the big one closes to the small one, it is accelerated. The underside of the small one becomes concave. And the big one becomes streamline shape. If the difference in volume between two bubbles is significant, the small one slides along the surface of the big one, and goes into the concave beneath it, then combines with it.