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The icing of wind turbine blades can cause changes in airfoil shape, which in turn significantly reduces the aerodynamic performance and affects the power generation efficiency of a wind turbine. In this paper, the iced airfoil shape of wind turbine blades with different positions, masses, and angles of attack icing was measured and modeled using 3D scanning technology, and changes in airfoil shape parameters under different icing conditions were obtained. The numerical simulations of icing blades were carried out to investigate the effect of blade icing on aerodynamic characteristics. The results show that ice accumulation thickness tends to increase nonlinearly along the spanwise direction and chord length for both windward and leeward icing. The airfoil angle of attack affects the trend of ice accumulation changes. As shown by the numerical simulation of the aerodynamic characteristic, blade icing changes the airfoil shape, which changes the pressure difference between the leading edge and trailing edge, affects the size and number of the wake vortex structures, and further changes the aerodynamic characteristics of the blade. [ABSTRACT FROM AUTHOR]

Coastal evolutions are expected to have a significant impact on storm tides, disproportionately aggravating coastal flooding. In this study, we utilize a nested storm tide model to provide an integrated investigation of storm tide responses to changes in coastline and bathymetry along the Zhejiang coasts. We selected coastline and bathymetry data from 1980 and 2016, as well as data from three typical typhoon events (i.e., Winnie, Haikui, and Chan-hom) for simulating the storm surge processes. The results indicate that changes in the coastline and bathymetry from 1980 to 2016 have resulted in an increase in storm tides in the northern part and a decrease in the central part of Zhejiang. Specifically, storm tides in Hangzhou Bay have increased significantly, with an average increase of about 0.3 m in the maximum storm tides primarily attributed to coastline changes. On the contrary, in smaller basins like Sanmen Bay, while reclamation itself has reduced peak storm surges, rapid siltation has consequently exacerbated the storm surge. By decomposing storm tides into astronomical tides and storm surges, we discovered that the change in tidal levels was twice as significant as the surge change. Moreover, the nonlinear tide–surge interaction was nearly four times that of the pure surge, significantly contributing to storm surge variation. Alterations in the momentum balance reveal that the water depth-induced bottom friction and wind stress increase contributes to the local enlargement of storm tides at the bay head, while the coastline changes exaggerate nearshore storm tides through an increase in the advection term. [ABSTRACT FROM AUTHOR]

Monitoring spatiotemporal changes in tidal wetlands under the disturbance of human activities provides a strong basis for coastal wetland protection and restoration. Long-term serial remote sensing images and other historical data were collected and analysed to investigate the distribution of tidal wetlands of Yueqing Bay in 1969, 1981, 1993, 2003, 2013, and 2021, a case study across the past 50 years. The data revealed that human activities cumulatively caused the net loss of approximately 59.62 km2 in area of tidal wetlands during the observation period. Firstly, between 1969 and 1993, reclamation primarily accounted for the variation of the tidal wetlands. Furthermore, between 1993 and 2013, the invasion of Spartina alterniflora and mudflat aquaculture also became important influencing factors. Between 2013 and 2021, development activities eased, and mangrove planting area increased. Over the analysis period, the overall results revealed that the tidal wetlands in Yueqing Bay underwent a transformation process from the relatively simple effects of exploitation by reclamation to the collective influence of combined exploitation and restoration, increasing the overall diversity of Yueqing Bay tidal wetlands over the study period. [ABSTRACT FROM AUTHOR]

Sea level rise (SLR) due to climate change is expected to alter tidal processes and energy transport, disproportionately affecting coastal communities. Utilizing a nested hydrodynamics model, we provided an integrated investigation of tidal responses to SLR in the Hangzhou Bay (HZB). The scenarios of SLR in the next hundred years count for both non-uniform trends based on historical altimetry data and uniform trends from the latest IPCC projections. In a comparison of model results under different SLR scenarios, we found that the tidal range is amplified by SLR in HZB with stronger amplification at the shallow southern coast. Tidal range change generally increases with the SLR scale; however, neglecting the heterogeneities in the spatial distribution of SLR tends to overestimate the SLR effects. The harmonic analysis illustrates that SLR exaggerates the dominated semidiurnal tides (M2 and S2) but dampens their overtides and compound tides (M4, M6, and MS4), of which M2 amplitude amplification explains 71.2–90.0% of tidal range change. SLR tends to promote tidal energy entering HZB through the Zhoushan Archipelago (ZA) compared to the prototype, while dampened sea-bed roughness and reduced tidal velocity come with a less dissipative environment in HZB, resulting in 6–18% more tidal energy exported upstream. Numerical experiments indicate ZA has significant effects on tidal responses and energy flux generation, therefore, its quantitative influences and physical mechanism are also discussed in this paper. [ABSTRACT FROM AUTHOR]

Combined with microstructure characterization and properties tests, the effects of Zn contents on the mechanical properties, corrosion behaviors, and microstructural evolution of extruded Al–Li–Cu–Mg–Ag alloys were investigated. The results show that the increase in Zn contents can accelerate hardening kinetics and improve the hardness of peak-aged alloys. The Zn-added alloys present non-recrystallization characteristics combined with partially small recrystallized grains along the grain boundaries, while the T1 phase with finer dimension and higher number density could explain the constantly increasing tensile strength. In addition, increasing Zn contents led to a lower corrosion current density and a shallower maximum intergranular corrosion depth, thus improving the corrosion resistance of the alloys. Zn addition, distributed in the central layer of T1 phases, not only facilitates the precipitation of more T1 phases but also reduces the corrosion potential difference between the T1 phase and the matrix. Therefore, adding 0.57 wt.% Zn to the alloy has an excellent combination of tensile strength and corrosion resistance. The properties induced by Zn under the T8 temper (solid solution treatment + water quenching + 5% pre-strain+ isothermal aging), however, are not as apparent as the T6 temper (solid solution treatment + water quenching + isothermal aging). [ABSTRACT FROM AUTHOR]