層化異重流於等速段之實驗分析

Experiments on Stratified Gravity Currents in the Slumping Phase

温博傑(Po-Jie Wen)

指導教授 ： 戴璽恆

國立臺灣大學/工學院/工程科學及海洋工程學研究所/碩士(2017年)

https://doi.org/10.6342/NTU201703903

摘要

本論文之研究之目的為探討層化重流體流入均質環境輕流體之運動現象。擬透過50組不同初始層化條件之定界交換水槽(lock-exchange)試驗，進行分層異重流於等速區段之實驗觀察。層化實驗中的初始條件設置由兩個無因次參數所控制，分別為其對應的驅動流體所佔有之鹽份質量比例關係(B*)及初始層化重流體的密度差異比(ρ*)，並探討等速區段與慣性區段之關聯性。結果顯示，等速段分層異重流之流動形貌與其福祿數值(Fs)將隨此二參數而有所改變。其中，當分層之條件為下層重流體主導(0 0.5)，而在上層主導則有小於此區間(Fs<0.45)之結果。

關鍵字

層化異重流 ； 表面形貌 ； 福祿數 ； 定界交換

並列摘要

The main purpose of this research is to investigate flow morphology caused by the penetration of density-stratified heavy current into light homogenous ambient fluid. For this reason, 50 different initial conditions of lock-exchange experiments are conducted to find out the influence of the density-stratified gravity current on slumping phase and the relation between slumping phase and inertial phase. These initial conditions depend on two controlling parameters, the density difference ratio (ρ*), and the distribution of driving buoyancy(B*). According to the experimental results, flow morphology and the Froude number of density-stratified gravity current will be changed by the two parameters in slumping phase. First, when currents are dominated by the lower-layer(00.5). In contrast, when upper-layer dominates the current, the Froude number will be lower than 0.45 (Fs<0.45), and the mixing between two layers is limited.

並列關鍵字

density-stratified gravity current ； morphology ； Froude number ； lock-exchange

參考文獻

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