针对波浪作用下的四柱结构近场干涉问题,应用势流理论对其现象与机理进行了研究.发现近场干涉发生时,柱群内侧流体发生共振运动,波高达到一个较大的峰值,且在波浪的多次反射作用下,最大波浪爬高出现在背浪侧圆柱的内侧,而柱群外侧及其中心处的波高则相对较低.同时,每根圆柱所受到的一阶水平波浪力均出现一个较大的峰值,这是圆柱两侧波高分布及相位关系共同作用的结果.二阶漂移力峰值主要与圆柱内外两侧波高有关,且当近场干涉发生时,圆柱的漂移力总是由群柱内侧指向外侧,使圆柱产生背离运动的趋势.
The near-trapping phenomena of a four-cylinder structure subject to water waves were investigated under the assumptions of potential theory.Numerical results show that resonant wave motion may occur inside the four-cylinder structure,which can lead to increased wave height and wave forces.The maximum run-up appears on the inner sides of the cylinders on the backwave due to the influence of repetitious fluid resonance and wave reflection.On the outer sides of cylinders and the center of the four-cylinder structure,the wave height is rather small.The peak values of one order horizontal wave force are observed on each cylinder due to the influence of wave height and phase-lag between the opposite sides of cylinder.The peak values of second order drift force are mainly dependent on the wave height between the opposite sides of cylinders.As near-trapping happens,the drift forces on the cylinders always point to the outsides of cylinders,making cylinders have the tendency of departing from each other.