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Zhijia Wu

Bio: Zhijia Wu is an academic researcher from Federal University of Rio de Janeiro. The author has contributed to research in topics: Stiffness & Bistability. The author has an hindex of 3, co-authored 7 publications receiving 38 citations.

Papers
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Journal ArticleDOI
25 Sep 2019-Energies
TL;DR: In this paper, an up-to-date review of the potential, technologies, prototypes, installed capacities, and projects related to ocean renewable energy including wave, tidal, and thermal, and salinity gradient sources.
Abstract: This study, firstly, provides an up-to-date global review of the potential, technologies, prototypes, installed capacities, and projects related to ocean renewable energy including wave, tidal, and thermal, and salinity gradient sources. Secondly, as a case study, we present a preliminary assessment of the wave, ocean current, and thermal gradient sources along the Brazilian coastline. The global status of the technological maturity of the projects, their different stages of development, and the current global installed capacity for different sources indicate the most promising technologies considering the trend of global interest. In Brazil, despite the extensive coastline and the fact that almost 82% of the Brazilian electricity matrix is renewable, ocean renewable energy resources are still unexplored. The results, using oceanographic fields produced by numerical models, show the significant potential of ocean thermal and wave energy sources in the northern and southern regions of the Brazilian coast, which could contribute as complementary supply sources in the national electricity matrix.

40 citations

Journal ArticleDOI
TL;DR: In this paper, a nonlinear stiffness mechanism installed in a floating point absorber (FPA) in regular waves allowed for studying the influence of the nonlinear behavior on wave energy harvesting.

18 citations

Journal ArticleDOI
TL;DR: In this article, an improved bistable mechanism composed of three linear springs was proposed, aiming to enhance the performance of a point absorber employed as a wave energy converter, which achieved high efficiency and robustness against power-take-off damping detuning and sea state changes.

15 citations

Journal ArticleDOI
TL;DR: In this paper, a point absorber (PA) wave energy converter (WEC) with a nonlinear stiffness system built by conventional mechanical compression springs (NSMech) is considered.

12 citations

Journal ArticleDOI
TL;DR: The reported research presents the double snap-through mechanism applied to a hemispheric point absorber type wave energy converter (WEC) to improve the energy absorption performance.
Abstract: Lower efficiencies induce higher energy costs and pose a barrier to wave energy devices’ commercial applications. Therefore, the efficiency enhancement of wave energy converters has received much attention in recent decades. The reported research presents the double snap-through mechanism applied to a hemispheric point absorber type wave energy converter (WEC) to improve the energy absorption performance. The double snap-through mechanism comprises four oblique springs mounted in an X-configuration. This provides the WEC with different dynamic stability behaviors depending on the particular geometric and physical parameters employed. The efficiency of these different WEC behaviors (linear, bistable, and tristable) was initially evaluated under the action of regular waves. The results for bistable or tristable responses indicated significant improvements in the WEC’s energy capture efficiency. Furthermore, the WEC frequency bandwidth was shown to be significantly enlarged when the tristable mode was in operation. However, the corresponding tristable trajectory showed intra-well behavior in the middle potential well, which induced a more severe low-energy absorption when a small wave amplitude acted on the WEC compared to when the bistable WEC was employed. Nevertheless, positive effects were observed when appropriate initial conditions were imposed. The results also showed that for bistable or tristable responses, a suitable spring stiffness may cause the buoy to oscillate in high energy modes.

4 citations


Cited by
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Journal ArticleDOI
06 Mar 2013
TL;DR: Tidal Energy: Like conventional hydroelectric dams, power plants are built on river estuaries and hold back huge amounts of tidal water twice a day which generates electricity when released as mentioned in this paper.
Abstract: Tidal EnergyLike conventional hydroelectric dams, power plants are built on river estuaries and hold back huge amounts of tidal water twice a day which generates electricity when released. India is expected to have 9,000 MW of tidal energy potential. Wave EnergyThis is generated by the movement of a device either floating on the surface of the ocean or moored to the ocean floor. Current EnergyIt is very similar to the wind above the oceans. Underwater turbines, large propellers tethered to the seabed, are moved with the marine currents to generate electricity. According to the Intergovernmental Panel on Climate Change (IPCC), given the scale of open ocean currents, there is a promise of significant project scale growth when technologies harness lower-velocity currents.

72 citations

Journal ArticleDOI
TL;DR: In this article, an adaptive bistable power capture mechanism is proposed for point absorber wave energy converters in regular waves, which is realized by two symmetrically oblique main springs together with two auxiliary springs and can adjust the potential function automatically to lower the potential barrier near the unstable equilibrium position.

60 citations

Journal ArticleDOI
01 Apr 2020-Energy
TL;DR: In this paper, the authors present an assessment of the technical potential of the offshore wind resources of the Southeast and South regions along the Brazilian coastline using atmospheric reanalysis databases, including CFSv2, ERA5 and MERRA2.

54 citations

Journal ArticleDOI
TL;DR: In this paper, a novel bistable electromagnetic wave energy converter is proposed, which includes a bio-inspired X-shaped supporting structure/mechanism and a mechanical-motion-rectifier.

35 citations

Journal ArticleDOI
Haicheng Zhang1, Ru Xi1, Daolin Xu1, Kai Wang1, Qijia Shi1, Huai Zhao1, Bo Wu 
15 Aug 2019-Energy
TL;DR: In this paper, a compact magnetic bistable mechanism is proposed to enhance the efficiency of a point wave energy converter (WEC) with a linear damper like Power Take-off (PTO) system.

31 citations