T型管廣泛見於各種工業管路系統中，包括了石化工廠、電子冷卻構裝應用、分子生物製程及電廠等，是各類運作環路中相當重要之部件。T型管能提供快速、短距離及成本低廉的低黏滯性流體混合可行方案。
在過去數十年間，單一進口角度T型管之同溫流體下游混合現象被廣泛地研究。然而在具有溫度差之混合效應及不同進口角度研究應用上，其相關聯的影響因子尚未完整的闡明。因此本研究將改變T型管支管之進口角度及擺放位置，並搭配調整主管與支管注水之體積流率比例或流速比，探討下游流體混合溫度及上游回流產生與否為主要研究目的，以闡明其各混合現象或參數之關聯。
本研究發現，在impinging jet形成、支管冷水衝擊到管路交接處底部之後，增加流速比之數值，會增強下游管路之混合情況，減少冷熱分層及溫度梯度。

T-junctions were the components which were cheap and low cost. T-junctions have been commonly employed in piping systems for industries, including petrochemical plants, electronic cooling applications, molecular biological processes, power plants, etc. T-junctions would be one of the solutions in the aspect of thermal mixing.
In the past, the related experimental research has been presented in the previous literature. However, the mixing effect and relative factors have not been discussed deeply. In the present work, a T-junction piping experimental system was installed for measuring the thermal mixing phenomenon. Experimentally, various angles of branch inlet and different directions of T-junction pipe have been introduced into these experiments. With the changing of the flow rate ratios or velocity ratios in the experimental conditions, the temperature variations of the thermal mixing along the downstream pipe and the formation of the reverse flow would be investigated.
The results showed that the appearance of reverse flow is relative to velocity ratio, defined as ratio of main pipe to branch pipe. The reverse flow in the main pipe would enhance the thermal mixing along the downstream.

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