Browsing by Author "Wang, Chao"

Now showing 1 - 5 of 5
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    Array analysis on a seawall type of deformable wave energy converters
    (Elsevier, 2024-03-24) Wei, Yujia; Wang, Chao; Chen, Wenchuang; Huang, Luofeng
    There has been a significant interest in developing Flexible Wave Energy Converters (FlexWECs) that utilise structural deformations to generate electricity and mitigate destructive wave loads to the devices. In the meantime, FlexWECs are most likely to operate in an array format to enhance space usage and power output, as well as provide convenience for maintenance. In this context, the present paper develops a high-fidelity computational model to investigate the interaction of ocean surface waves with an array of seawall-type FlexWECs, which can meanwhile serve coastal engineering purposes. The fluid field is solved using the Navier-Stokes equations, and structural deformations are predicted using a nonlinear finite-element method. Hydroelastic interactions of up to seven deforming FlexWECs with the surrounding wave fields are demonstrated through systematic simulation cases. Based on the simulation results, analyses are conducted to investigate how the wave farm energy output is influenced by the gap between individual devices and the number of devices deployed. Accordingly, empirical design suggestions are provided. Overall, this work innovatively simulates the hydroelastic interactions between waves and multiple deforming structures, and the provided insights are useful for promoting the development of FlexWECs and their wave farms.
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    Efficient gas adsorption using superamphiphobic porous monoliths as the under-liquid gas-conductive circuits
    (American Chemical Society, 2019-06-14) Wen, Min; Peng, Cheng; Yao, Ming; Wang, Chao; Ming, Tingzhen; Peng, Biaoling; Huang, Fuzhi; Zhong, Jie; Cheng, Yi-Bing; Zhang, Qi
    The gas–liquid membrane contactor forms a gas–solid–liquid interface and has a high potential for the applications in gas adsorption, catalysis, energy exchange, and so on. Porous superhydrophobic membranes show a great gas separation/adsorption ability. However, the complicated device architecture and the durability issue are normally concerned especially for the continuous circulation of gas and liquid. In this work, we present a free-standing gas-conductive circuit simply formed by connecting the superamphiphobic porous monoliths (SAPMs) to achieve an efficient under-liquid gas adsorption. The porous worm-like SAPM is prepared with low-temperature expandable graphite and polyvinylidenefluoride, exhibiting superamphiphobicity and superaerophilicity after fluoridation. The as-made SAPM circuits can be used as a reliable gas conductor under numerous liquids, such as water, alkaline, acidic, and oily solutions. In this work, the CO2 adsorption capacities of the SAPM circuits are evaluated under NaOH and methyldiethanolamine solutions and the mass transfer rate can reach up to 9.61 mmol m–2 s–1. Moreover, the effective human blood oxygenation process is also demonstrated using SAPM circuits. Thus, the reported SAPM provides an alternative gas–liquid exchanging method and the simplified process could be of great benefit to the cost-effectively large-scale CO2 capture or gas exchanging applications.
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    Hydroelastic modelling of a deformable wave energy converter including power take-off
    (Elsevier, 2024-11-01) Wang, Chao; Wei, Yujia; Chen, Wenchuang; Huang, Luofeng
    Given the advantages of flexible wave energy converters (FlexWECs), such as deformation-led energy harnessing and structural loading compliance, there has been a significant interest in FlexWECs in both academia and industries. To simulate the FlexWEC interaction with ocean surface waves, a 3D computational fluid-structure interaction approach is developed in this study. The fluid and solid governing equations are discretized using finite difference and finite element methods, respectively. An immersed boundary method is used to couple the two independent grid systems. A novel numerical technique is introduced to model the dielectric elastomer generator (DEG) as the power take-off (PTO). The wave energy capture performance is analysed for different PTO configurations and at various wave conditions. Based on the obtained results, the PTO damping coefficient and the relative wavelength range that maximizes the capture width ratio (CWR) are determined. The wavefield results also reveal the presence of wave-height enhancement and attenuation points around a single FlexWEC, providing potential site selection references when deploying multiple FlexWECs in an array.
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    Interactive effects of deformable wave energy converters operating in close proximity
    (Elsevier, 2024-11-01) Wang, Chao; Wei, Yujia; Chen, Wenchuang; Huang, Luofeng
    Flexible wave energy converters (FlexWECs) have been gaining increasing research and industrial interest as their deformable nature can potentially remedy the structural issues that limit the development of rigid WECs. To maximise the usage of space and infrastructure and improve energy efficiency, FlexWECs are normally deployed in close proximity, where the wave interaction with one device can influence others, signifying the opportunity to obtain energy efficiency enhancement from the interactions. To investigate the power capture performance of a FlexWEC array, this study employed a validated three-dimensional high-fidelity computational method to simulate the wave interaction with three FlexWECs in various array arrangements including power-take off. Based on systematic simulation cases, the present work analysed the relation between the geometrical characteristics of an isolated FlexWEC's perturbed wave field and the array's overall energy capture efficiency. The constructive interaction of the array was found the strongest when the longitudinal and lateral spacings of the array were 0.6 and 1 times of incident wavelength respectively, with a 15 % enhancement of overall captured energy compared to three devices operating in isolation. Overall, this study provides insights into the fluid-structure interaction of waves with multiple deformable structures, facilitating the modelling and planning of FlexWECs.
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    Proanthocyanidins-induced horizontal arrangement poly(vinyl alcohol)/graphene composites with enhanced mechanical properties
    (Wiley, 2019-03-19) Wang, Chao; Wen, Min; Guo, Le; Zhang, Boyu; Ming, Tingzhen; Huang, Fuzhi; Zhang, Qi
    A green approach is employed to prepare mechanically enhanced composites by adding noncovalently proanthocyanidin (PC)‐modified graphene (PC‐rGO) into poly(vinyl alcohol) (PVA). Ascorbic acid (AA) is used as the reducing agent, and PC is used as a dispersant to synthesize low‐defect and fully dispersed graphene. After static treatment, the PC‐rGO sheets in the composite form a horizontally arranged structure. Compared with neat PVA, the Young's modulus of the graphene‐modified composites is significantly enhanced by approximately 79.3% with incorporation of 0.9 wt% PC‐rGO. The composites incorporated with GO or AA‐rGO (without PC) have randomly distributed GO structures and apparent rGO agglomeration, resulting in a weaker mechanical property. The dispersibility, degree of defects, distribution state of graphene, and interactions with the polymer matrix are directly related to the final mechanical performance. This new approach to mechanically enhance graphene‐embedded PVA composites provides the possibility for large‐scale production of graphene‐reinforced composite materials.