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采用数值方法对5×5定位格架棒束通道的阻力特性进行研究。采用常用的减小弹簧、刚凸高度,使其与燃料棒间留有微小间隙的方式对格架进行几何建模,发现计算得到局部阻力系数明显小于实验值,分析原因并参考面接触的思路,提出改进的格架几何模型,并采用不同湍流模型进行数值模拟,得出SST模型计算的结果与试验值符合很好。利用改进的模型研究搅混翼及其他部件的阻力特性,发现搅混翼在格架局部阻力系数中所占的比重很小,但其引发的横向流使格架下游的摩擦阻力增加。
The resistance of the 5 × 5 locating grids is studied numerically. Geometry modeling of the lattice was carried out by using the commonly used method of reducing the spring and the height of the convexity and leaving a slight gap between it and the fuel rods. It was found that the calculated local resistance coefficient was obviously lower than the experimental value. , An improved grid geometric model is proposed and different turbulence models are used to simulate the numerical results. The results of SST model are in good agreement with the experimental values. Using the improved model to study the drag characteristics of the mixing wing and other components, it is found that the mixing wing has a small proportion of local drag coefficient, but the transverse flow induced by it increases the frictional resistance downstream of the grid.