【摘要】：采用多普勒超聲測速儀(ADV),對小寬深比的U型彎道沿程斷面上各不同垂線位置上的點(diǎn)進(jìn)行了三維流速測量,并基于所測數(shù)據(jù)分析了主流線位置、橫向流速沿垂線分布、環(huán)流結(jié)構(gòu)以及環(huán)流強(qiáng)度等水力特性。研究結(jié)果表明:在60°斷面后,水流的表層與底層主流線開始分離,形成復(fù)雜螺旋結(jié)構(gòu)。水流進(jìn)入彎道后,沿程各斷面均形成一逆時針主環(huán)流,并且從75°斷面開始,凹岸表層又出現(xiàn)與主環(huán)流方向相反的次生環(huán)流;環(huán)流強(qiáng)度最大值位置出現(xiàn)在彎道彎曲度1/3處附近。研究結(jié)果為進(jìn)一步深入研究彎道水流紊動特性和泥沙運(yùn)動提供了有效參考。
[Abstract]:The Doppler ultrasonic velocimeter (ADV), is used to measure the three-dimensional velocity at different vertical positions along the section of U-shaped bend with small aspect ratio. Based on the measured data, the hydraulic characteristics such as the position of the main streamline, the distribution of transverse velocity along the vertical line, the circulation structure and the circulation intensity are analyzed. The results show that after 60 擄section, the surface layer of the flow begins to separate from the main streamline of the bottom layer, forming a complex spiral structure. After the water flow enters the bend, an inverse time needle main circulation is formed along each section, and from the 75 擄section, the secondary circulation opposite to the main circulation direction appears on the surface of the concave bank, and the maximum circulation intensity appears near 1 鈮，

本文編號：2503225