Influence of turbulence on the drag of solid discs and turbine simulators in a water current
Influence of turbulence on the drag of solid discs and turbine simulators in a water current
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DOI：
10.1007/s00348-013-1637-9
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发表时间：
2013
影响因子：
2.4
通讯作者：
T. Blackmore;W. Batten;G. Műller;A. Bahaj
中科院分区：
文献类型：
--
作者：
T. Blackmore;W. Batten;G. Műller;A. Bahaj
用实验室实验研究了湍流对实心圆盘和多孔圆盘涡轮模拟器阻力的影响。这些圆盘被引入到重力供给的水槽中的湍流中，具有不同水平的湍流强度和积分长度尺度。湍流是使用三种不同的网格配置产生的，其产生的强度和规模与之前的风洞研究相当。阻力测量是用两种不同直径和孔隙率的圆盘在有和没有上游网格的情况下进行的。实验结果表明，所有被测圆盘的阻力系数都显著地依赖于湍流强度和积分长度尺度。对于较小的整体长度尺度，相对于圆盘，当湍流强度大于13%时，阻力系数收敛，在低强度情况下，阻力系数增加约20%。在湍流强度为10%的实验中，当整体长度比例与圆盘直径之比约为50%时，阻力系数最小。因此，在具有不同特性的湍流中运行时，圆形钝体的阻力系数预计会有很大的变化。
Laboratory experiments have been used to investigate the effects of turbulence on the drag of both solid discs and porous disc turbine simulators. These discs were introduced to turbulent flows, in a gravity-fed water flume, with various levels of turbulence intensity and integral length scales. The turbulence was generated using three different grid configurations, which produced intensities and scales comparable with previous wind tunnel studies. The drag measurements were taken with discs of two different diameters and porosities with and without the upstream grids. The experimental results have demonstrated that the drag coefficients, of all the discs tested, are significantly dependent on both the turbulence intensity and integral length scale. For small integral length scales, relative to the disc, the drag coefficients converged for turbulence intensities greater than 13 %, with an increase of around 20 % in drag coefficient over the low-intensity case. Experiments with turbulence intensities of 10 % demonstrated minimum drag coefficients when the integral length scale-to-disc diameter ratio was around 50 %. Significant variations in the drag coefficient of circular bluff bodies are therefore expected when operating in turbulent flows with different characteristics.