A tidal pump for artificial downwelling: Theory and experiment

Xiao, Canbo; Fan, Wei; Qiang, Yongfa; Xu, Zhenyu; Pan, Yiwen; Chen, Ying

doi:10.1016/j.oceaneng.2017.12.066

Cited by 16 publications

(20 citation statements)

References 16 publications

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“…Subsequently, a numerical analysis on the device using Computational Fluid Dynamics (CFD) was proposed to predict the pumping performance, the findings of which showed consistently accurate predictions with experimental results [14]. A tidal pump could pump surface oxygen-rich water to a depth of 15.36 m below the pycnocline at a flow rate of 0.4 m 3 /s in the Changjiang Estuary [9]. The device, named a tidal pump and consisting of a 90 • bend and a vertical downwelling pipe, was designed to mitigate hypoxia in the Changjiang Estuary, China, where hypoxia frequently occurs below the pycnocline during late summer.…”

Section: Introductionmentioning

confidence: 91%

“…Compared with the one previously proposed by Xiao et al (2018), we found by experiments that the pump with rectangular section and auxiliary parts is more efficient in generating downwelling flow. Moreover, the current device has a concrete base, which is suitable for the shallow water system like Muping marine ranch, while the tidal pump given by Xiao et al (2018) aims at deeper coastal oceans [9].…”

Section: Design Of the Tide-induced Device For Artificial Downwellingmentioning

confidence: 99%

“…This principle can be formulated as the kinetic energy head is equal to the sum of the density difference head and all the local losses. It has been extended for artificial downwelling to analyze the turbulent flows without regarding the explicit structure of the flow distribution [9]. The energy balance equation can be written as follows.…”

Section: Theoretical Analysismentioning

confidence: 99%

“…This practice can pump oxygen-rich surface waters into the oxygen-deficient bottom waters, strengthen the below-pycnocline ventilation, increase the dissolved oxygen concentration in the bottom waters and consequently mitigate bottom hypoxia. Artificial downwelling devices include thermal energy-powered devices, electric-powered devices, wave-powered and tide-induced devices [6][7][8][9] (Table 1). A density current generator (DCG) powered by solar energy and fossil fuel, with the aim of improving water quality in Gokasho Bay, was proposed by the University of Tokyo, Japan, in 2006 [6,10].…”

Section: Introductionmentioning

confidence: 99%

“…Fortunately, there are ample tidal energy resources in coastal hypoxia areas, which can be utilized to strengthen vertical water exchange in aquaculture zones. The authors have published one paper on a tidal pump for artificial downwelling, and the reader is referred to these for detailed information on the general principles of construction and the factors which affect it [9]. In this study, based on the theories of Xiao et al (2018), we further optimized the structure of the tube, added the concrete base and mixer, thus enhancing the efficiency of the downwelling device and its applicability in marine ranching.…”

Section: Introductionmentioning

confidence: 99%

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Experimental Study on the Performance of an Innovative Tide-Induced Device for Artificial Downwelling

et al. 2019

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Hypoxia has been increasingly observed in estuaries and coastal marine ecosystems around the world. In this paper, a tide-powered artificial downwelling device is proposed to potentially alleviate hypoxia in bottom waters. The downwelling device mainly consists of a vertical square tube, a 90° bend sitting on the top of the tube, two symmetrical-guide plates which installed alongside the vertical tube, a static mixer, and an artificial reef. Scale model experiments are performed with respect to different density difference heads, horizontal current velocities, and tube geometries. The results show that the downwelling flow rate is dependent on horizontal current velocity, tube geometry parameters, and the density profile of ambient water. In addition, increasing the equivalent diameter and bend radius of the device can decrease the total loss coefficient in the tube, which in turns enhance the downwelling efficiency. The two symmetrical-guide plates also generate obvious downwelling of surface water which further improves the whole performance of the device. Further work will need to determine the influence of the other parts of the device, such as the static mixer and artificial reef, on the downwelling efficiency.

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Section: Introductionmentioning

confidence: 91%

Section: Design Of the Tide-induced Device For Artificial Downwellingmentioning

confidence: 99%

Section: Theoretical Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Experimental Study on the Performance of an Innovative Tide-Induced Device for Artificial Downwelling

et al. 2019

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Experimental study on parametric configurations of artificially downwelling aerations in stratified water

Tian,

Wang,

Zhang

et al. 2023

Appl Water Sci

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Downwelling aeration has become a widely applied approach to cope with the water eutrophication in stratified reservoirs, rivers and lakes. The aeration parameters involving flow rate, flow locations and working periodicity and their impacts on the temperature and dissolved oxygen (DO) distributions of water have been largely unclarified, causing extra time and energy consumptions in practice. In this study, a home-built water tank and an aeration pump are used to model the downwelling aeration processes in stratified water. Temporal influences of aeration parameters on the water stratifications and eutrophicated elements are systemically investigated, with the purpose of searching parametric configurations to enhance the anti-eutrophication efficiency. It is found that the variation rates of temperature destratification and DO distribution in the water body could be saturated and strongly correlated with the flow rate. Based on such experimental saturation rates, we find an optimized working condition from the aspect of energy saving: a 300 rpm pump speed and a 15 cm distance between the flow exit and the sediment surface. In such conditions, the total nitrogen and phosphorus dissolved in the bottom layer of water decrease exponentially with aeration time, and can be reduced by 53.8 and 86% in the first 6 h of aerations, respectively, taking full advantage of the microbial bonding to the sedimentations. The present work provides better understandings for efficient implementations of downwelling aerations.

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Experimental and numerical study of current-induced artificial upwelling

Fan

Xiao

et al. 2019

Applied Ocean Research

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A tidal pump for artificial downwelling: Theory and experiment

Cited by 16 publications

References 16 publications

Experimental Study on the Performance of an Innovative Tide-Induced Device for Artificial Downwelling

Experimental Study on the Performance of an Innovative Tide-Induced Device for Artificial Downwelling

Experimental study on parametric configurations of artificially downwelling aerations in stratified water

Experimental and numerical study of current-induced artificial upwelling

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