The wind speed distribution with height is analysed by using hourly data for a full year recorded at 6 levels of a 164 m tower at Nanjing. A statistical error analysis shows that power law and logarithmic law are best applicable when the wind is strong. For the height range from 16 to 164 m, the power law represents the actual speed distribution better than does the logarithmic law. 相似文献
The geometrical dimensions of a frozen-ground enclosure for a low-temperature storage reservoir are determined from a static designstorage reservoir are determined from a static design on the assumption of a safe excavation of ground in digging the trench. Neglecting the combined work of the enclosure and surrounding thawing rock mass, the problem is reduced to the design of the frozen-ground shell, stressed along its outer contour by the thawing ground pressure.
To estimate the tension of the wall of an enclosure it is sufficient to use the solution of the problem of a thick-walled tube subjected to ambient pressure. It is difficult to find a sufficiently simple analogue for the problem of the bottom. The solution of the plate-bending problem locates the neutral line in the middle of the section when there are equal tensile and compressive stresses at the inner and the outer contour. If the combined work of the bottom of the section and the wall is taken into account, the neutral line shifts from the centre of the bottom to the inner contour of the enclosure, i.e., the compressive stresses exceed the tensile ones, which is of particular importance for materials with different resistance to compression and tension. 相似文献
