Papers by Keyword: Wind Force

Abstract: In order to design a double buoys mooring system in the estuary of Yalu River for loading work of 40,000 tons of bulk cargo ship, the article mainly based on the practicality of the meteorological condition of this sea area and the data of the vessel as well as the national criterion, do some calculations of wind force, current force, wave force as well as the total force on the ship, with the calculation result to make a designation of double mooring buoy system, decide the size of the mooring buoy, the size and length of the chain, the size and the depth of the Deadman. The construction according to the designation has a good effect; the method of calculation and the designation are proved useful.

Abstract: The liquid-gas flow is proposed to accurately simulate the offshore environmental state. The aerodynamic feature is estimated using the three-dimensional model of horizontal-axis wind turbine with NRELS809 series aerofoil by means of the simulating software tool of FLUENT. The variable speed is implemented via the six different wind speeds. The calculated results show that the similarly evolutional tendency of velocity occurs in the wake region when operating at the six variable speeds. The stall speed is related to blade height and wind speed. The small blade height or large wind speed also leads to the serious stall phenomenon. The total force is conducted to estimate the potential capability for leeward and windward surface to capture wind power. The calculated results reveal that the larger wind speed facilitates generating the more magnitude of total force. However, the velocity and force feature for the wind turbine has the especially rapid change at the wind speed of 6 m/s, which perhaps results from the intrinsic geometry and configuration.

Abstract: In this review the current status of research on electromigration of hydrogen in metals and alloys is determined. Experimental data and theoretical developments over the past 16 years are gathered and are put in perspective with older literature. Theory has reached a level at which the current induced wind force on a proton in a metal can be estimated quantitatively. At the same time empirical data have become more decisive as well. In experiments on a number of alloys the wind force could be effectively eliminated, revealing information on the direct force in electromigration. In metals, as a function of increasing temperature or sample resistivity, the effective valence of hydrogen slowly approaches unity. Combining theoretical and experimental results, s· strong support in favour of a direct force on a proton in an electron gas in presence of an electric field is found. The direct valence is close to unity or somewhat less due to screening effects. Theoretical analysis shows that only in the dilute limit, at low temperatures, complete screening of the external electric field is expected. At elevated temperatures a gradual break-down of the screening by the electron gas is found to be intimately related to the electron-phonon interaction gaining in strength. As far as the hydrogen-deuterium isotope effect in the effective valence of hydrogen in metals is concerned, results from different experiments are often found to be inconsistent. Combination of a zero point motion model with isotope dependent lattice deformation seems to be most promising in explaining some of the observations.