Exploration on Wave-Structure Interaction Laws and Output Performance of Coaxial Hybrid Energy Harvester Based on a Large-Scale Wave-Current Flume

In order to address the challenge of the wide application of hybrid energy harvesters based on triboelectric-electromagnetic effect in actual ocean environments, it is crucial to execute hydrodynamic tests conformed to the actual ocean environments and conduct field tests. Here, a coaxial hybrid energy harvester (CH-EH) is prepared, and its hydrodynamic behaviors are investigated systematically through a large-scale wave-current flume. The verification test of the CH-EH output performance is carried out offshore at the port of SanDun, Qinzhou. The results show: 1) The CH-EH can achieve high output (U > 380 V, I > 2.4 mA) under small regular wave excitation (H > 0.15 m), and it maintains high output (U > 220 V, I > 1.8 mA) over a wide range of regular wave frequencies (0.6 Hz < f < 1.1 Hz). 2) The output performance of the CH-EH under irregular wave excitation is lower than that under regular wave excitation. The variation trend of the CH-EH output performance obtained in actual ocean tests is similar to that obtained in the laboratory, but slightly lower than that obtained in the laboratory. 3) The output performance of the CH-EH is positively correlated with its draft depth, and the ocean current inhibits its output performance.