Gravity currents generated by constant inflow on a lateral unconfined slope

• Main Authors: Li-Chung Hsu, 徐立中
• Other Authors: 戴璽恆
• Format: Others
• Language: zh-TW
• Published: 2017
• Online Access: http://ndltd.ncl.edu.tw/handle/18748002684644769600

碩士 === 國立臺灣大學 === 工程科學及海洋工程學研究所 === 105 === 　　This thesis examines gravity currents generated by the constant inflow on a lateral unconfined slope. The slope angle and input discharge are the controlling factors to determine the configuration of gravity currents. From the experimental results of gravity currents, as increasing the slope of inclined bottom, the evolving structures become more slender and thinner in current width and depth, respectively. In dimensional analysis, the front position of gravity currents associated with the power-law relation,〖(x_(v,f)〗^(4/3)~t(W_p)^(1/3)f(θ) and (∆ρ/ρ)〖(x_(v,f)〗^(-5/3)g~(W_p)^(2/3)f(θ), is derived, except for the small angle 0^°、3^°. In addition, the flow pattern is categorized as two regions, namely steady region (body of gravity current) and unsteady region (the current head). By quantifying characteristic parameters of these two region, we found K_2、K_3、α_v1、α_v2 increase and K_1、K_5 decrease as slope increases. Also, Gravity currents front velocity increases and density difference decreases as slope increases. Finally, we observe shape ratio coefficient k decreases as the discharges increases. Keywords: gravity currents, unconfined slope, constant inflows, density difference, characteristic parameters.