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Elastomeric support utilizing steel-reinforced elastomeric bearing pads (SREBPs) has been applied to offshore structures gradually. This study presented a process for designing the offshore elastomeric support. And a specific numerical method was introduced to synchronously simulate the hydrodynamic responses and structural interactions between hull and topside modules of a spread-moored floating production storage and offloading (FPSO) unit with elastomeric-supporting topside modules. Furthermore, a model test of the target FPSO was conducted in a deepwater offshore basin to validate the numerical simulation, and the numerical results were consistent with the experimental outcomes overall. The numerical results demonstrated that both bearing force and stress of the SREBPs fell within the design scope, and the maximum bearing force on vertical SREBPs was found to be around 1.3 times the weight of a corresponding topside module, considering the dynamic effects resulted from motion responses of the FPSO. Additionally, the maximum bearing force acting on anti-uplift SREBPs can refer to the peak value of a vertical SREBP's dynamic force correspondingly. The horizontal interactions between hull and topsides mainly depend on inclination of the hull, so the bearing forces of horizontal SREBPs are closely related to the severity of rolling and pitching. • A process is presented for the design of offshore elastomeric support for the topsides of an FPSO. • A numerical method is introduced for the simulation of an FPSO with elastomeric-supporting topsides. • The hydrodynamic responses and structural interactions are simulated synchronously for the FPSO. • The model test of a spread-moored FPSO with elastomeric-supporting topsides was performed creatively. • The numerical method is proved to be accurate and applicable for the engineering practice. [ABSTRACT FROM AUTHOR]

Parenting a child with autism spectrum disorder (ASD) can be more stressful and discouraging than parenting a child with typical development, especially during the COVID-19 pandemic. This study aimed to unpack the factors and processes contributing to resilience among parents of children with ASD and the difficulties they faced during the COVID-19 pandemic lockdowns in a City in China (Macau SAR). We conducted individual, in-depth, semi-structured interviews with 16 parents of 13 children with ASD (11 mothers and 5 fathers; M age = 42.36 years; 12 boys and 1 girl; M age = 8.08 years). Data was analyzed using a qualitative thematic analysis approach. Overall, the results revealed several noteworthy themes: stressors, mental health, marital relationships, individual resources, social support, coping strategies, and resilience. The findings of this study deepen our understanding of the challenges that parents of children with ASD face, by identifying factors and processes contributing to resilience during the lockdowns enforced during the COVID-19 pandemic. This is especially relevant in a city like Mainland China where there is a dearth of various support resources for families that have children with special needs. Limitations, implications, and future directions are discussed. • Parents perspective on the parenting difficulties they faced during the COVID-19. • The interrelationship of resilience, stress, and coping strategies were identified. • Increasing awareness of ASD may help reduce the stigma and build resilience. [ABSTRACT FROM AUTHOR]

This study focuses on the wet-towing transportation of an FPSO with elastomeric-supporting topside modules. In the study, an approximation method is utilized to calculate the wet-towing resistance in the design sea state for determining the wet-towing configuration. Meanwhile, the study successfully achieves to simulate the hydrodynamic responses and structural interactions synchronously for the complex wet-towing system. This numerical method is applied to the feasibility analysis of the wet-towing configuration in the design sea state, which indicates that the mean wet-towing resistance, peak towline tension, and dynamic responses of the FPSO are all within the design scope, proving that the wet-towing configuration is feasible. A parameter sensitivity analysis is performed for the wet-towing transportation, which reveals that the increase in towing speed and severity of sea state results in larger towing resistance. Extending the towline length has a significant dampening effect on both peak towline tension and its fluctuation during extreme sea state. The excursions of wind, wave, and current incident directions from the towing route can lead to the offsets of the FPSO, so an auxiliary tug is necessary to keep the FPSO in the planned route, and the wet tow in head sea is recommended. • The numerical method of wet-towing transportation is verified to be applicable by model test. • The approximation method of towing resistance calculation is proved to be accurate through numerical simulation. • The method introduced to determine the wet-towing configuration for the FPSO turns out to be feasible. • The hydrodynamic responses and structural interactions are simulated synchronously for the wet tow of the FPSO. [ABSTRACT FROM AUTHOR]

The aim of this work was to study an improved solvent evaporation method to prepare poly (lactic acid) (PLA) microspheres via foam-transfer. Since the foaming process and its transfer were critical to the improved method, they have been studied. Additionally, the delivery capability of foams was studied as a function of the oil/water ratio, the stirring rate, the concentration of polyvinyl alcohol (PVA) and ethanol (EtOH) in the aqueous phase (ω PVA, ω EtOH). It was found that foaming varied during the preparation process and it influenced the properties of PLA microspheres. When the oil/water ratio (w/w) ≥ 3:10, stirring rate ≥ 600 r/min, ω PVA ≥ 1 wt%, and ω EtOH = 0 wt%, solvent evaporation was able to produce enough foams for foam-transfer, which helped to deliver more than 89 wt% PLA microspheres to the receiving vessel. However, ω PVA ≤ 0.3 wt% and ω EtOH = 20 wt% were unfavorable for maintaining the spherical shape of PLA microspheres and caused the aggregation. The methodology was further used to prepare azoxystrobin-loaded PLA microspheres successfully with a high encapsulation efficiency of 86.54%. This work is meaningful since it enables an efficient and continuous route to prepare functional biodegradable polymer microspheres. [ABSTRACT FROM AUTHOR]

A series of 2-(((5-akly/aryl-1 H -pyrazol-3-yl)methyl)thio)-5-alkyl-6-(cyclohexylmethyl)-pyrimidin-4(3 H)-ones were synthesized and their anti-HIV-1 activities were evaluated. Most of these compounds were highly active against wild-type (WT) HIV-1 strain (IIIB) with EC 50 values in the range of 0.0038–0.4759 μmol/L. Among those compounds, I-11 had an EC 50 value of 3.8 nmol/L and SI (selectivity index) of up to 25,468 indicating excellent activity against WT HIV-1. In vitro anti-HIV-1 activity and resistance profile studies suggested that compounds I-11 and I-12 displayed potential anti-HIV-1 activity against laboratory adapted strains and primary isolated strains including different subtypes and tropism strains (EC 50 s range from 4.3 to 63.6 nmol/L and 18.9–219.3 nmol/L, respectively). On the other hand, it was observed that those two compounds were less effective with EC 50 values of 2.77 and 4.87 μmol/L for HIV-1A 17 (K103N + Y181C). The activity against reverse transcriptase (RT) was also evaluated for those compounds. Both I-11 and I-12 obtained sub-micromolar IC 50 values showing their potential in RT inhibition. The pharmacokinetics examination in rats indicated that compound I-11 has acceptable pharmacokinetic properties and bioavailability. Preliminary structure–activity relationships and molecular modeling studies were also discussed. A series of novel S -DABO derivatives as potential HIV-1 inhibitors were designed and synthesized. Selected compounds displayed potent activity against different HIV-1 strains. Preliminary structure−activity relationships, pharmacokinetics and molecular modeling of these novel congeners were investigated. Image 1 [ABSTRACT FROM AUTHOR]

The equal-height-difference passive heat removal system (EHDPHRS) utilizes the ocean environment as an infinite heat sink that can better suit ocean nuclear power plants (ONPPs). However, a structure with an equal-height-difference can easily cause reverse flow of subcooled water, leading to serious condensation-induced water hammer (CIWH). In this paper, a fully visual experimental facility with same geometric characteristics as the EHDPHRS was established with the aim of studying the CIWH phenomenon. First, two kinds of CIWH modes were observed by the results of the visual experiment, namely the intermittent CIWH and the continuous CIWH. The typical feature of the intermittent CIWH is that the single-phase natural circulation occurs intermittently. Then, the converging-diverging structure (CDS) was designed to avoid the CIWH events in the EHDPHRS. The effectiveness of CIWH prevention was evaluated employing the velocity field, which was obtained by the PIV experimental system. It was found that the CDS can effectively inhibit the further reverse flow of subcooled water and thus eliminate the triggering mechanism of CIWH events. Finally, a dimensionless number was used to balance CIWH prevention and natural circulation capacity. It was shown that when the dimensionless number is in the range of 0.67–0.80, the CDS can eliminate the CIWH events while ensuring the natural circulation capacity. • A fully visualized experimental device is built to study the CIWH phenomenon in the EHDPHRS. • Two types of CIWH modes are determined by combining visual image with thermal–hydraulic parameters. • Typical characteristics of intermittent CIWH is the intermittent occurrence of the single-phase natural circulation. • The CDS is designed to avoid the CIWH events and experimental verifications are carried out. • CDS effectively inhibits the further reverse flow of subcooled water and eliminate the CIWH formation. [ABSTRACT FROM AUTHOR]

• The transient flow characteristics in the EHDPHRS are studied by experiment. • The formation mechanisms of flow mode are found out by thermal-hydraulic parameters. • The CIWH events are the severe two-phase natural circulation flow instability in the EHDPHRS. • Occurrence position of the CIWH events affects the two-phase natural circulation ability. The equal-height-difference passive heat removal system (EHDPHRS) utilizes the ocean as the heat sink for infinite heat dissipation and has broad application prospects in ocean nuclear power plants. However, the equal height difference between the heat source and heat sink is susceptible to severe flow instability. In this study, a fully visualized experimental facility was constructed to analyze the transient flow characteristics in the EHDPHRS. The experimental results revealed three typical two-phase natural circulation flow modes in the EHDPHRS. The formation mechanism of each flow mode was analyzed using thermal–hydraulic parameters. The results revealed that the flow mode is determined by the steam–water direct contact condensation and reverse flow of subcooled water, and both factors promote each other. Moreover, condensation-induced water hammer (CIWH) was found to be the most severe flow instability in the EHDPHRS. CIWH events can lead to violent pressure peaks and reduce the natural circulation capacity. In addition, when the occurrence position of CIWH events is concentrated at the pipe outlet, the influence of CIWH events on the two-phase natural circulation flow capacity gradually decreases. These research results aid in the optimal design of the EHDPHRS and prevention and control of CIWH events. [ABSTRACT FROM AUTHOR]

Ice resistance of icebreaker navigating in ice area is the main reference index for the ship design and the selection of the main engine. Researchers gradually use the numerical simulation method to study ice resistance and its influencing factors because of the development of computer technology. But there are few studies on the effect of sea ice flexural strength on ice resistance in the numerical simulation. In this study, a method was proposed to simulate the change of sea ice flexural strength numerically by changing the parameters of the sea ice material model, so as to realize the influence analysis on ice resistance. Firstly, the material model that can realize the simulation of the icebreaker running ahead in level ice was determined. Then, the parameters of the material model affecting the flexural strength numerically were determined. Taking the material model adopted in this paper as an example, the parameters were plastic failure strain, Young's modulus, and compressive yield strength. Finally, the value criterion of influence parameters was put forward in the given design space and applied to the numerical simulation of the icebreaker running ahead in level ice. It was demonstrated that the method could realize the influence of sea ice flexural strength on ice resistance in the numerical simulation. This study is a new attempt in the numerical simulation of the icebreaker running ahead in level ice and it can help ship designers to analyze the navigation performance of icebreakers in different ice areas. • A new method was proposed to simulate the change of sea ice flexural strength numerically by changing the parameters of the sea ice material model, so as to realize the influence analysis on ice resistance. • The influence parameters that can be changed to numerically alter the flexural strength of the sea ice material model were determined by the four-point bending numerical model of the ice beam. • The influence parameter selection criteria for sea ice material models with different flexural strengths was proposed. [ABSTRACT FROM AUTHOR]

The difference frequency wave drift force may excite large resonant responses for a moored FPSO in horizontal motions, so the moored FPSO responds in both low frequency motion and wave frequency motion generally. In this study, the parameter sensitivity analysis is carried out to investigate the motion response characteristics of a spread moored FPSO in the bidirectional sea state comprised of wind sea and swell. The effects of water depth, loading condition, existence of mooring system, numerical method, sea state type, significant wave height and wave direction on the motion responses are studied in numerical simulation. The research shows that the wave frequency motion responses of FPSO are dominated by swell, and the low frequency motion responses are contributed from both wind sea and swell in the bidirectional sea state. The motion responses are proved to be affected indistinctively by the change of loading condition. The change of water depth affects the motion responses in some degrees. The responses of FPSO in roll can be enlarged by the spread mooring system, and the enlargement becomes more significant if the spread mooring system is arranged in deep water with large pretension force for the mooring lines. • A validation study is conducted to verify the numerical method of the hydrodynamic calculations for FPSO. • The low frequency responses of FPSO in surge and sway increase remarkably with the decrease of water depth. • The existence of spread mooring system affects the motion responses of FPSO in roll, especially in deep water. • The wave frequency motion responses are dominated by swell while the low frequency ones are contributed from wind sea and swell. • The horizontal motions are resulted from the coupling of low frequency drift motions and wave frequency oscillations. [ABSTRACT FROM AUTHOR]

The offshore elastomeric supporting style via steel reinforced elastomeric bearing pads (SREBPs) has been in use gradually. In this study, the elastomeric supporting style used for the interfaces between topsides and stools is adopted by a spread mooring FPSO to analyze the responses of SREBPs and evaluate the applicability. Firstly, the motion responses of target FPSO are numerically simulated to check if the mooring system is safe. Then, the hydrodynamic responses are taken as the boundary conditions of hull for the multibody dynamic simulations. In the simulation, a compression spring model is proposed to equivalently replace the SREBPs. The stiffness of equivalent compression springs is obtained by linear fitting of the stiffness data from finite element analysis of SREBPs. Finally, the multibody numerical results show that the SREBPs can reach into yield state, but if there are assistant devices helping to limit the deformations, the SREBPs would work well. The largest deformations of SREBPs are observed to be sensitive to the hydrodynamic responses, so the SREBPs can still reach into yield state in extreme case. In that condition, it is recommended to bond the topsides to the stools and the numerical results confirm that it is available. • A validation study is conducted to verify the numerical method of the hydrodynamic calculations for FPSO. • The finite element method is consistent with model test in the stiffness calculations. • The stiffness of elastomeric bearing pad is linearized in a small range of deformations in design. • A compression spring model is proposed to equivalently replace the steel reinforced elastomeric bearing pads. • The viscous damping of equivalent compression springs is equivalently transformed into Rayleigh damping. [ABSTRACT FROM AUTHOR]

The equal-height-difference passive heat removal system (EHDPHRS) via natural circulation driving and utilizes ocean as infinite heat sink for heat dissipation, showing broad application prospect in ocean nuclear power field; but the heat removal pipe normally encounters the reverse flow of cool seawater into the pipe, leading to operation instability and even condensation-induced water hammer. In this study, the integration of volume of fluid model and condensation model based on surface renewal theory is used to simulate the reverse flow characteristics in the heat removal pipe under single-and two-phase natural circulation conditions. The interfacial heat and mass transfer are calculated by user-defined functions (UDF). The numerical results reveal that the buoyancy force (F b) and condensation driving force (F Δ P ) both accelerate the reverse flow, while the inertial force (F i) restrains the reverse flow; the reverse flow length presents monotonous decrease with increasing the flow velocity under single-phase conditions and parabolic-like trend for two-phase flow. A prediction correlation for the reverse flow length is developed using dimensionless Reynolds number, Grashof number and vapor volume fraction, covering single- and two-phase conditions. The predicted reverse flow length by the correlation agrees with 94% of the results within deviations of ± 15%. [ABSTRACT FROM AUTHOR]

The investigation of transient flow behaviors of gas-liquid two-phase flow under ocean conditions is vital to the application of gas-liquid transport in ocean engineering area. In this paper, the gas-liquid two-phase flow numerical model of rolling horizontal pipe is established based on CFD code combined with user-defined functions (UDF). The three-dimensional rolling flow fields are simulated using the volume of fluid (VOF) model, RNG k − ε turbulence model and additional inertia force method. First, the simulation results are compared with the experimental data, which revealed a reasonable agreement. Then, the variation in transient flow behaviors by horizontal pipe (L = 2.0 m, D = 0.035 m) with varying rolling conditions (θ m = 2 ° - 6 ° , T = 0.5–4.0 s) and flow velocities (j G = 0.1–10.0 m/s, j L = 0.1–0.5 m/s) are investigated. The results showed that the rolling motion caused agglomeration of dispersed bubbles and gas slugs into a continuous gas column, increased the cross-sectional void fraction significantly. The variation of additional inertial force and pressure drop increased with the increase of rolling angle and the decrease of the rolling period. Compared with the rolling angle, the transient flow behaviors are more sensitive to the rolling period. In addition, as the initial gas volume fraction increased, the effects of rolling motion on the transient flow behaviors decreased gradually. These qualitative conclusions may serve as a reference for gas-liquid transport simulations under rolling conditions. • A numerical model of gas-liquid two-phase flow under rolling condition is developed. • The rolling motion increased the cross-sectional void fraction significantly. • Pressure drop increases with increasing rolling angle and decreasing rolling period. • The transient flow behaviors of two-phase flow are more sensitive to rolling period. [ABSTRACT FROM AUTHOR]

The Eulerian–Eulerian two-fluid model (TFM) in combination with the kinetic theory of granular flow (KTGF) and the Johnson and Jackson boundary condition is widely used to simulate multiphase flows in engineering. However, this model requires the calibration of several parameters. One of these parameters is the specularity coefficient, which characterizes the particle–wall collisions. Thus far, research on this parameter has been lacking in the field of slurry flow simulations. In this study, the integration of TFM with KTGF and the Johnson and Jackson boundary condition is used to simulate the transportation of sand–water slurry in horizontal pipes. The effects of different specularity coefficient values on the predicted solids wall shear stress, velocity, and concentration are analyzed. It is found that the solids wall shear stress increases with the specularity coefficient and is more sensitive to the smaller specularity coefficient. As the specularity coefficient increases, the profiles of the solids velocity and concentration are rotated clockwise, shifting the maximum velocity point to a higher vertical location and producing a plumper solids concentration profile. These qualitative conclusions may be used as a reference for the specularity coefficient tuning process in the field of slurry transport simulations. • The wall shear stress of the solid phase is more sensitive to the smaller specularity coefficient. • A larger specularity coefficient provides a less symmetrical solids axial velocity profile. • A larger specularity coefficient distributes the particles more homogeneously. • An increasing specularity coefficient rotates the profiles of the solids axial velocity and concentration clockwise. [ABSTRACT FROM AUTHOR]

Icebreaking vessels will probably be collided by sea ice from different directions when they are moored or dynamically positioned. It may form serious ice rubble accumulations and cause large ice loads. In the present study, numerical models on an icebreaking vessel that interacted with level ice at different ice drift angles were established based on the FEM-SPH adaptive method to simulate the above situations. The effects of ice drift angle and speed were investigated. The primary goal of this study is to expound on the reasons for the formation of ice rubble accumulation and the influence of different parameters through motion analysis of SPH particles. It was demonstrated that the ice rubble motion is the direct reason for the related phenomena, while the ice drift angle and speed are the fundamental reasons. The ice drift angle has a decisive effect on ice rubble accumulation and icebreaking force. When the heading angle is 90°, the force in the ship width direction reaches the maximum value and the value is 2.22 MN, which is much higher than that of 0° example. Vessels need to change the position of collision with the sea ice to avoid this situation. The research in this paper is a good supplement to the model test. It is helpful to further understand and analyze the interaction between moored or dynamically positioned icebreaking ships and level ice. • Ice rubble accumulation was simulated by FEM-SPH adaptive method. • The reasons for the ice rubble accumulation were presented and analyzed. • The effects of ice drift angles and ship speeds on ice rubble accumulation were investigated. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline Mg2Si with high purity, homogeneous composition and uniform particle size was successfully synthesized by a facile hydrogen-driven chemical reaction at below 500°C. The as-prepared Mg2Si exhibited an improved Li-ion storage ability as anode material for Li-ion batteries as it delivered an initial capacity of about 1095mAh/g at 100mA/g. The discharge capacity stayed at 406mAh/g after 60cycles, which is much better than that of the commercial Mg2Si anode and previously reported Mg2Si anode synthesized by mechanical alloying. The proof-of-concept synthesis technique presented in this work should be valuable for the preparation of other intermetallic compounds with difference of melting point between the constituent elements. [Copyright &y& Elsevier]

• ZFO/NCFs act as self-standing electrode under high sulfur loading. • ZFO as efficient chemical anchor to adsorb polysulfides and inhibit shuttle effect. • ZFO as polysulfides conversion catalyst to accelerate the redox kinetics. Lithium-sulfur (Li-S) battery is regarded as a hotspot in the research field of next-generation energy storage with a theoretical specific capacity of 1675 mAh g−1 and an energy density of 2600 Wh g−1. However, the short cycle life and poor lithium transport kinetics are restricted its real-world applications. Hence, the combination of electrospinning technology and subsequent hydrothermal method acts as an effective strategy to synthesize the ultrafine zinc ferrite nanoparticles decorated on nitrogen functionalized porous carbon nanofibers (ZFO/NCFs). Three-dimensional ZFO/NCFs act as self-standing electrode for Li-S batteries. The presence of ZFO nanoparticles is beneficial for adsorbing lithium polysulfides and inhibiting the shuttle effect. Additionally, ZFO nanoparticles exhibit an excellent catalytic effect of the polysulfides conversion in redox reactions. As a result, the cell of ZFO/NCFs delivers a high initial discharge capacity of 1100.8 mAh g−1 and after 300 cycles the discharge capacity reaches 789.7 mAh g−1 (coulombic efficiency: average 98.7%) at 0.2 C under 5.75 mg sulfur loading. Moreover, the initial capacity of ZFO/NCFs is 10.23 mAh and remains 7.21 mAh at 12.15 mg sulfur loading after 120 cycles. Hence, ZFO/NCFs contribute to adsorption and catalysis, which shows a promising exploration for the design of cathode materials of Li-S batteries. [Display omitted] [ABSTRACT FROM AUTHOR]

The specularity coefficient is an important input parameter in the Johnson and Jackson boundary conditions. Thus far, research on this parameter has been lacking in the field of slurry flow simulations. In this study, the integration of the Eulerian–Eulerian two-fluid model with kinetic theory of granular flow and Johnson and Jackson boundary conditions is used to simulate the transportation of sand–water slurry in horizontal pipelines. A range of flow conditions, including high and low velocities, high and low concentrations, coarse and fine particles, and large and small pipes, is considered to study the effect of the specularity coefficient on the predicted hydraulic gradient. Then, the simulation results are compared with previous experimental measurements to determine the appropriate values of the specularity coefficient. The hydraulic gradient is found to be positively correlated with the specularity coefficient; in addition, it is more sensitive to the specularity coefficient when the specularity coefficient is less than 0.1. The appropriate value of the specularity coefficient decreases with the flow velocity and increases with the solid volume fraction. In the range of flow conditions considered, the findings may be used as a reference for future simulations in the research field of slurry transport. • The hydraulic gradient is positively correlated with the specularity coefficient. • The hydraulic gradient is more sensitive to the smaller specularity coefficient. • The appropriate value of the specularity coefficient decreases with flow velocity and increases with solids concentration. • Particle and pipe diameters have a combined impact on the appropriate value of the specularity coefficient. [ABSTRACT FROM AUTHOR]

The introduction of a β-carbonyl group to the C-2 side chain of S-DABO led to the finding of a series of novel potent anti-HIV agent. Some derivatives proved to be highly effective in inhibiting HIV-1 replication at nanomolar concentrations. Furthermore, the novel S-DABOs differ from the classical NNRTIs in that some compounds are active against both HIV-1 and HIV-2. They might interfere with another target or at least act on RT in a different way as compared to typical NNRTIs. [Copyright &y& Elsevier]

3D-ordered catalyst electrodes have been recognized as one effective strategy to reach high current density operation for proton exchange membrane fuel cell (PEMFC) applications. Gas diffusion electrodes (GDEs) with platinum nanowire arrays in-situ grown on gas diffusion layer (GDL) surface is an important contribution in this area, but the performance is highly dependent on the GDL surface properties. In this study, the GDLs available in the market are systematically investigated, with a focus on the influence of the GDL surface properties on the in-situ growth of Pt nanowire arrays to fabricate GDEs as cathodes for PEMFCs. The experimental results indicate that mesopores especially micropores play a key role. They enable a hydrophilic surface for the isopropanol pretreated GDL, facilitating the in-situ growth of Pt nanowires to form a uniform array with a large electrochemical surface area (ECSA), finally leading to a high-power density. With Freudenberg H24CX483 carbon paper GDL, the highest power density of 0.9 W cm−2 is achieved. The understanding achieved here could be further used to develop novel GDLs for fabricating the next generation of electrodes for large current density operations. [Display omitted] • The surface wet ability of GDLs plays a critical role to fabricate Pt nanowire array electrodes. • Mesopores especially micropores leading to hydrophilic surface after isopropanol treatment. • Uniformly distributed nanowire arrays enable large ECSA finally a high power density. • Freudenberg H24CX483 carbon paper GDL shows the best property for this application. [ABSTRACT FROM AUTHOR]

The model test is important in the design and analysis of floating offshore wind turbines. However, the rotor thrust generated by the scaled model blades will be far less than the Froude-scaled value in the wave basin test, which has a significant effect on motion responses of floating offshore wind turbines. Thus, in order to improve the reliability of model tests, it is essential to simulate the rotor thrust accurately based on the aerodynamic similarity. In the present study, four parametric models were developed to define the geometry of model blades and they were integrated separately into the optimization model to reach the design criteria. Considering the weight control, the model blade defined by high-order design method was tested. It was demonstrated that the deviation between the experimental and numerical model blades under the rated condition was very small (only 3.16%). Under the same condition, the model blade with aerodynamic similarity could improve the rotor thrust by 106.33% compared with the Froude-scaled model blade. Simultaneously, high-order redesign method can significantly reduce the blade weight. Thus, the high-order redesign method is considered to be an effective way to eliminate the scale effect in the model tests of floating offshore wind turbines. • High-order redesign method to eliminate the scaling effect in the model test of floating offshore wind turbines. • A new method to obtain model blades with the lightest weight considering aerodynamic similarity. • Model test was conducted to test the rotor thrust of redesigned model blades. • A good correlation with experimental data and numerical results. [ABSTRACT FROM AUTHOR]

• A fully visualized experimental facility combined with PIV system was designed to study the reverse flow phenomenon in the EHDPHRS. • Single-phase reverse flow velocity is proportional to heating power and inversely proportional to subcooled-water temperature. • Two-phase reverse flow velocity increases first and then decreases with heating power. • Buoyancy lift induced by density difference and pressure difference induced by direct contact condensation are the driving force for reverse flow. • Flow inertia force caused by forward flow is the restraining force for reverse flow. The equal-height-difference passive heat removal system (EHDPHRS) has a large potential in floating nuclear power plants (FNPPs) due to its ability to fully utilize the marine environment to achieve residual heat removal. However, the horizontal connection between the heat sink and the heat source could easily lead to the subcooled-water reverses flow and thus trigger serious flow instabilities. In the present paper, a fully visualized experimental set was built, combined with a particle image velocity (PIV) system to investigate the subcooled-water reverses flow in the EHDPHRS. First, PIV observations clearly highlighted five flow stages during a complete natural circulation, including the reverse flow occurred in the single-phase and two-phase flow. Then, it was shown that the single-phase reverse velocity is proportional to heating power and inversely proportional to subcooled-water temperature. While, the two-phase reverse velocity increases first and then decreases with the increase in heating power. Moreover, the two-phase reverse flow phenomenon shows obvious periodicity. Finally, the buoyancy force (F b) caused by the density contrast, and the pressure difference (F Δ P) caused by the direct contact condensation (DCC) are the triggering forces for the reverse flow, while the flow inertia force (F i) caused by the forward flow represents the restraining force. [ABSTRACT FROM AUTHOR]