This study experimentally investigates the development and decay of bound energy fractions due to positive and negative interactions (b²_p and b²_n, respectively) applying bispectral analysis. It was revealed that the Ursell number is the most successful parameter to estimate the variation patterns of b²_p and b²_n. The experimental waves included 27 waves with three offshore wave heights, three periods, and three offshore water depths propagating over a mild slope of 1:30. A wide variety of wave nonlinearity and bound coupling intensities were observed across the experimental dissipative surf zone. For a wave propagating toward the shore, the corresponding Ursell numbers for the relative maximum values of b²_p and b²_n are 0.27 and 0.22, respectively. The ratio of significant wave height to water depth corresponding to these extreme values for positive and negative triads are ~0.4 and ~0.32, respectively. The highest values of b²_p and b²_n for a progressive wave can be predicted as a function of the Ursell number using two new proposed experimental formulations. The sub-harmonics are more persistent during wave-breaking conditions than super-harmonics due to lower wave steepness. The biphase values of self-coupling of the spectral peak are attained negative for waves with Ursell numbers greater than 0.35.

本研究通过应用双谱分析，通过实验研究了由于正负相互作用（分别为b ² _p和b ² _n）引起的束缚能分数的发展和衰减。结果表明，Ursell数是估计b ² _p和b ² _n变化模式最成功的参数. 实验波包括27个波浪，具有三个离岸波高、三个周期和三个离岸水深，在1:30的缓坡上传播。在实验耗散海浪区中观察到了各种各样的波非线性和束缚耦合强度。对于向海岸传播的波，b ² _p和b ² _n的相对最大值对应的Ursell数分别为0.27 和0.22。与这些极值对应的有效波高与水深之比分别为~0.4 和~0.32。b ² _p和b ²的最高值可以使用两个新提出的实验公式将行进波的_n预测为Ursell数的函数。由于较低的波陡度，次谐波在破波条件下比超谐波更持久。对于Ursell数大于 0.35 的波，光谱峰的自耦合双相值达到负值。