Experimental study on hydrodynamic characteristics of an array of innovative wave-driven water exchange devices with heaving buoys in regular and irregular waves. (15th October 2021)

• Record Type: Journal Article
• Authors: Jiang, Xiutao; Yin, Zegao; Miao, Yipei
• Is Part Of: Ocean engineering. Volume 238(2021)
• Publication Date: 2021-10-15
• Subjects: Hypoxia -- WDWE device -- Heave amplitude -- Outlet flow rate -- DO concentration; Ocean engineering -- Periodicals; Ocean engineering; Periodicals; 620.4162
• DOI: 10.1016/j.oceaneng.2021.109717
• Languages: English
• ISSNs: 0029-8018

Abstract

Abstract: To alleviate the hypoxia in bottom seawater, an array of innovative wave-driven water exchange (WDWE) devices with heaving buoys was proposed to transport superficial oxygen-rich water to deep hypoxic zones. The hydrodynamic characteristics of the devices arranged in an in-line square configuration were experimentally investigated under regular and irregular waves. It is found that the characteristic heave amplitudes and flow rates increase with increasing wave height and wave period. The average heave amplitudes and flow rates in regular waves are larger than the significant heave amplitudes and flow rates in irregular waves. The relative heave amplitudes decrease but the non-dimensional outlet flow rates increase with increasing wave steepness. Generally, the characteristic heave amplitudes and flow rates of the upstream device are higher than those of the downstream device in regular and irregular waves. The water intake depth has a negative effect on the characteristic heave amplitudes and flow rates. Finally, the variation in the oxygen transfer coefficients was analyzed. The results show that the oxygen transfer coefficients under the device effect are a few orders of magnitude larger than those without the device effect. This indicates that the array of WDWE devices can effectively enhance DO concentration in bottom waters. Highlights: An array of WDWE devices in an in-line square configuration was proposed to solve hypoxia in bottom seawaters. The heaving response and the flow process were investigated with four different water intake depths. The characteristic heave amplitudes and outlet flow rates in regular waves were compared with those in irregular waves. The effect of the WDWE devices on the oxygen transfer coefficient variations was analyzed.