2017-08-012024-05-14https://scholars.lib.ntu.edu.tw/handle/123456789/657569摘要：異重流，又稱為密度流因流體密度差異所自然產生之流動現象。環境中造成密度差異的原因可能是溫差、溶解物質、懸浮泥沙等。異重流在流體力學當中不但是個經典的例子，在水利、海洋、大氣及工程相關領域皆有相當多的實際案例。 筆者於2014年榮幸獲得邁頂計畫-深耕型研究計畫，執行致2016年已成功建構三維異重流於不同斜坡實驗，及所需之設備。並且針對密度差小之情形，稱為「布氏異重流」，於不同斜坡之運動已經有初步成果。為延續先前努力成果，並且有更新的突破。故筆者提出本次計畫,提供研究團隊能持續研究。 筆者根據之前努力結果以及累積的研究經驗，進一步將異重流分為二類討論：1. 連續與非連續入流 2. 布氏（密度差異小）與非布氏（密度差異大） 此兩類型。先前研究中，大多記載為非連續之入流實驗，僅少數相關研究提供我們了解自然界連續入流之運動型態， 在自然環境中，例如：豪雨沖刷河床產生之異重流亦屬於此類。本研究將更進一步的分析連續入流之異重流的流動。且在自然環境中，密度差異相當多變，在此次計畫中，我們也將針對密度差異較大之「非布氏異重流」加以討論分析。 文獻中，極少有三維環境之異重流實驗相關發表，但實際應用上卻處處可見。在此，筆者有幸建置之三維環境實驗，所設計之實驗皆領先世界其他團隊，為補足文獻上缺塊，筆者抓住此次機會更進一步討論不同入流情形，以及密度差異對於異重流之影響。本計畫所獲致之成果不僅是學術領域上有所貢獻，更有助於相關領域評估三維限環境中影響，於理論及實際皆有指標意義。且根據本研究團隊長期於斜坡異重流研究之經驗及技術，必定能更有效的完成本次研究，並發表於世界首屈一指之期刊，且能在國際間發光發熱。 <br> Abstract: Gravity currents also known as density currents, are driven by a density difference. The density difference can be attributed to a number of factors, including temperature differences and dissolved or suspended materials. Gravity currents are not only one of the classical problems in fluid mechanics but also play an important role in geology, oceanography, meteorology, and engineering. During 2014 and 2016, PI has prepared all of the equipment which is needed in three-dimensional experiment in different slope. With some achievements, the PI focused on Boussinesq gravity currents in different slope in an unconfined environment with a quantitative volume. Boussinesq approximation is known as the sufficiently small density difference between the heavy fluid and the light one. In order to continue the previous work, and make a breakthrough of research, the PI propose new proposal to offer our group to make new studies. Based on experience and previous achievements, the studies of gravity currents can be classified in two groups on the buoyancy source (which is continuous and discontinuous inflow), and the density contrast (which is Boussinesq and non-Boussinesq gravity currents). In previous research, is less be consider on gravity currents propagation in a continuous inflow. But in the nature flow with a continuously maintained discharge is very common. For example, after a heavy rain, the flood causes riverbed erosion and sediment suspension, which perform a gravity current flow into a reservoir or a continental shelf. Moreover, the density difference between the heavy fluid and the light one are quite large in natural environment. Therefore, we also focus on large density contrast (non-Boussinesq) gravity currents experiment in this research. In the literature, three-dimensional gravity currents experiments are few records, but in many application or environment, three-dimensional environment is pretty common. It is pleasure for PI could successfully construct the three dimensional experiment at last year, and this is a good opportunity for us to design some groundbreaking experiments to investigate the problem of three-dimension gravity current. Further, we will mainly focus on two influencing factor of gravity currents in different slope. One of the influencing factor is buoyancy source, and the other is influence by density contrast. This proposed project not only creates a new breakthrough of gravity currents in academic but establishes the fundamental theory which can be a scientific basis for practical application in engineering. Due to our research group study for gravity currents for long years, the techniques and experiences are well developed. We will definitely finish the project effectively, and our research can be published in most prestigious journals in fluid mechanics.異重流密度差斜坡流量水槽實驗Gravity currentsdensity differenceslopedischargechannel experiment