混流的機制

Mechanism of Flow Mixing

李灝(LI,HAO)

指導教授 ： 潘瑋

國立中正大學/理學院/物理學系/碩士(2016年)

摘要

本論文是研究不可壓縮流體匯流的現象。在封閉管內流體的體積流率與管面積、壓力、流體的型態有關，管壁結構粗糙程度關係到近管壁流的流速，管面積又牽涉到流體的型態為層流與否；這兩因素疊加會直接影響到流速與體積流率。然而不同管徑之管流匯流之後先有予各別面積為比值的的混合比例，會因為匯流之後的總開口面積改變，造成面積比值混合比例加上非線性變化項的額外體積流率改變。流的水流量比例會隨著匯流後出水口大小的改變而有所變化。我們於實驗中找出兩水管匯流其混合比例與開口大小的關係，並驗證兩管匯流並非是兩單一管管流的線性疊加。
實驗中觀察得知匯流後水流是否能夠完全填充滿匯集管會影響混合比例的穩定度，為了使水分子在管口處能保有足夠的內聚力，不致使空氣填入混流槽， 在匯流處加了適合的芯有效縮小出水口處的面積，在穩定混流比例的同時也減少大小管對沖而致使較小管路的阻塞，提高本實驗的精準度。
我們得知出水孔變化對各別管道體積流率的變化量，進而使用擬合技巧回推以匯流後開孔面積為變數的各管體積流率方程式，更進一步可以推知混流後流體的各種狀態，例如：混流後溫度、濃度、淤積量…等等。

關鍵字

混合流體

並列摘要

This thesis is to study the phenomenon of mixing with incompressible fluid. In tube, the volume flow rate of the fluid is related to: tube area, pressure, fluid patterns, the pipe wall roughness also effect the volume flow rate of the flow near the wall of the tube, and the cross-sectional area of pipe involved in a laminar flow patterns of fluid or not; These two factors will directly affect velocity and volume flow rate. However, after streams from different diameters of pipe combined then got a mixing ratio of the respective area ratio, because of the exit area changed, resulting in the ratio with an additional volume flow rate change of non-linear terms. The proportion of water flow will changed with exit area size varies. We found out the relationship between the water mixing contribution with exit area size changed in experiments, and to verify the two pipes contribution isn’t linear superposition of two single tube flow ratio.
After the experiment was observed that the water is able to completely fill the mix cistern or not, will affect the stability of the mixing ratio, in order to make the water molecules in the exit of mix cistern can retain enough cohesion, not to cause air fill the slot, so at the confluence added a suitable core effectively shrink the area of the mix cistern, while the proportion is stable also avoided hedge blocking, improving the accuracy of the experiment.
We know the amounts of individual volume flow rate within varying the exit hole size, and thus use of fitting techniques to deduce volumetric flow rate equation of variable exit hole size, and further can infer various states after the fluid mixed for example: temperature, concentration, sedimentation volume ... and so on.

並列關鍵字

Flow Mixing

參考文獻

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