平直沙坝海岸叠加波浪的裂流试验

Experimental study of rip currents by intersecting wave on barred beach

为研究叠加波浪场的裂流特征,在平直沙坝海岸地形进行了叠加波浪形成的沿岸波高周期性变化的裂流试验研究。试验中叠加波浪是由波浪在垂直岸线的丁坝反射所形成的两列交叉波浪叠加产生,交叉波浪是具有等频率但入射角相反的两波列。通过对叠加波浪节腹点垂直岸线位置浪高的测量和沙坝范围内沿岸布置的声学多普勒测速仪流速测量结果来分析沙坝海岸丁坝反射波形成的裂流特性,讨论了波浪节腹点对裂流位置和裂流空间尺度的影响。对不同周期情况在x=5 m沙坝顶处的速度剖面对比,分析了不同周期对裂流的影响。

To better understanding the characteristics of rip current by intersecting wave,the experimental study of rip currents by intersecting wave on the barred beaches was conducted. The intersecting wave trains in the experiment were created by reflecting of obliquely incident waves on a vertical wall which stands perpendicular to the coastal line.The two intersecting waves are with the same amplitude and frequency,but opposite angle. The results of the distribution of wave heights,set-up of the mean level by wave gauges and velocity measuring by ADVs,are shown for analyzing the characteristics of rip currents on barred beaches. The influence of nodes and antinodes on the location and spacing of rip current is investigated. The effect of wave period to rip current is analyzed by the velocity distribution of rip currents of different periods on the top of sandbar.