Experimental study of blockage effect on the dynamic behaviors of a tapered net system under wave-current actions

To intercept the marine organism aggregation and floating debris from the coastal nuclear power plants, the innovative net pouch system has been commonly adopted across the cooling water intake channel. Subjected to the wave-current actions, the fouled net pouches are apt to excessive deformation and dynamic response, which has not been illuminated sufficiently. To combat this, a series of large-scale physical model tests is delved into the blockage effect on the dynamic properties of the net system. Due to pure current and current-wave combinations, the tensile forces on the supported devices are measured and analyzed both in time domain and frequency domain, considering various wave periods, wave heights and current velocities. Particularly, the effect of the net span width is examined for a more advanced realms of configuration. The results show that unlike the fixed-beam arrangement, the anchored bottom of the net pouch witness noteworthy low-frequency force and a significant offset in the peak frequency of wave-induced tension. The blockage effect speeds up the rising trend of these tensions against the current velocity, resulting in an exacerbated force uniformity. Owing to additional anchor lines, the increasing number of nets in a span is beneficial to improve the force distribution and tension synchrony among the mooring lines.