表面粗糙度对双曲冷却塔风压分布的影响

对不同粗糙条参数组合下冷却塔风压分布进行测试,分析粗糙度对平均风压和脉动风压的影响.研究结果表明:粗糙条宽度b对风压分布影响较小,而粗糙条高度k和数量n影响较大;粗糙度系数k/s能较准确描述粗糙度大小,当k/s一致时,不同粗糙条数量n与高度k组合下的平均风压基本一致,但高度大的脉动风压小;粗糙度对正压分布和背压大小影响较小,而最小负压系数幅值、脉动风压系数峰值随粗糙度的增大而减小,背压稳定区宽度则略有扩大;尽管通过增大模型表面粗糙度能有效地在较低雷诺数条件下实现高雷诺数下的平均风压分布,但脉动风压模拟的准确性需要通过大型冷却塔风压实测进行验证.

Influence of Modal Surface Roughness on Wind Pressure Distribution of Hyperbolic Cooling Tower

The wind pressure distribution of cooling towers with different rough strip parameters was tested, and the influence of roughness on both mean and fluctuating wind pressure was investigated. The experiment results show that the width of rough strip has little effect on the distribution of wind pressure, while the height and number have a greater impact, and the roughness coefficient k/s can describe the size of roughness accurately. Even though the number n and height k of rough strip is different, as long as the roughness coefficient k/s is consistent, the mean pressure distribution is basically the same, but the peak fluctuating pressure is smaller with higher height of rough strip. Furthermore, roughness has little effect on both the distribution of positive pressure and the size of back pressure. However, the amplitude of the smallest negative pressure coefficient and the peak fluctuating pressure decrease with the increase of roughness, while the width of back pressure expands slightly. Although the mean pressure at high Reynolds number can be simulated effectively at low Reynolds number by increasing surface roughness, the simulation accuracy of fluctuating pressure should be checked with field tests in the future.