流線具象化觀察試驗

Abstract

中文摘要

藉由此實驗，可以觀察到各種不同型狀的物體在不同流速以及不同相對角度之流場中所產生的流線變化，以及停滯點與分離點的位置，尾部之不同拖曳情況，邊界所產生之影響，以及觀察液體流經不同形狀的固體邊界時的流動現象等等。也可以觀察當流量大小不同時，層流與紊流的發生。有此透過觀察實際現象來體會課本上抽象理論，也提升對流體力學之間得直覺。 此實驗所使用的設備為流線演示儀，而流線的觀察是利用染劑噴頭注入流場內所產生的染料線流經固體邊界時之變化，觀察出停滯點、分離點、層流、紊流等等現象。 由實驗結果可以得知，流體流經固體邊界時會因為摩擦力的因素與固體邊界產生速度梯度，而最靠近固體邊界處之流速為零，也因為摩擦力之影響而產生分離點。此實驗之應用常見於水工構造物、壩體建置前模擬計算水流經過之受力以及流速。

Abstract Through this experiment, we can observe the changes of flow lines in different flow fields and different relative angles of flow field, as well as the position of stagnation point and separation point, the different drag of tail, the boundary As well as the flow phenomena observed when liquids flow through different shaped solid boundaries. It can also be observed when the flow rate is different, the laminar flow and turbulence occur. This is through the observation of the actual phenomenon to understand the textbook abstraction theory, but also enhance the intuition between the fluid mechanics. The equipment used in this experiment is a streamline demonstrator, and the observation of the streamline is the change of the dye lines generated when the dye jet is injected into the flow field through the solid boundary to observe the stagnation point, the separation point, the laminar flow, Turbulence and so on. From the experimental results, we can see that when the fluid flows through the solid boundary, the velocity gradient will be generated due to the friction factor and the solid boundary, and the flow velocity near the solid boundary is zero, and the separation point is generated due to the frictional force. The application of this experiment is common in hydraulic structures, the dam before the simulation to calculate the flow through the force and flow rate.