海滩湿润沙面起动摩阻风速的风洞实验

摘要/Abstract

摘要： 风蚀是一种重要的地貌过程和地质灾害，它影响海岸沙丘的增长，加速土地沙漠化并危害沿岸建筑。沙面湿度强烈影响沙粒的临界起动风速和沙面稳定性，因此，也是影响风蚀过程的一个重要因子。本项风洞实验使用华南热带湿润海岸的海滩沙，研究了表面湿度（1 mm 深）对海滩沙风蚀起动的影响，建立了一个新的预测热带湿润海滩湿沙起动摩阻风速的模型，该模型指明给定粒径下，湿沙的起动摩阻风速随ln100 M（M，重量湿度）线性增加。初步评价了7个预测湿沙起动摩阻风速的模型。实验结果表明,各模型的预测结果间存在着很大差异。在0.0124(M1.5)的湿度下，不同模型预测的湿沙起动摩阻风速比观测的干沙起动摩阻风速大了34%~195%。在湿度小于0.0062(0.5 M1.5)时，Chepil 和Saleh的理论模型和实验数据很吻合；在湿度大于0.0062(0.5 M1.5)时，Belly的实验模型和实验数据更趋一致。

关键词: 起动, 湿度, 风蚀, 风洞实验, 热带湿润海岸

Abstract: Wind erosion is one kind of important geomorphology processes and geological disasters, which has significant impacts on dune growth and desertification, and causes damages to architecture on sea coasts. The moisture of sand surface layer greatly affects the threshold wind velocity and sand stability, thus, it is also one of the important influence factors on wind erosion. In this study, we investigated the influence of surface moisture content at 1-mm depth on sand erosion in tropical humid coast of southern China, and established a new predicting model. The modeling results indicated that the threshold friction velocity increased linearly with increasing of ln100M (M is gravimetric moisture content) in condition of given sand diameters. Evaluation was given to seven popular models for predicting the threshold friction velocity on moisture sediments, and found that there were significant differences among their predicted results. At a surface sand moisture content of 0.0124 (M1.5), the predicted threshold friction velocity predicted by the seven models were 34% to 195% larger than the observed threshold friction velocity on dry sands; at a surface sand moisture content of lower than 0.0062 (0.5 M1.5), the predicted values by models of Chepil and Saleh well matched the experimental data; but when surface sand moisture content of more than 0.0062 (0.5 M1.5), the data simulated by the Bellys empirical model were seem same as the experimental data.

Key words: entrainment, moisture content, wind erosion, wind tunnel experiment, tropical humid coast

中图分类号:

X169

韩庆杰;屈建军;张克存;俎瑞平;廖空太;牛清河. 海滩湿润沙面起动摩阻风速的风洞实验[J]. 中国沙漠, 2011, 31(6): 1373-1379.

HAN Qing-jie;QU Jian-jun;ZHANG Ke-cun;ZU Rui-ping;LIAO Kong-tai;NIU Qing-he. Wind Tunnel Experiment of the Threshold Friction Wind Velocity on Wet Beach Sand Surface[J]. JOURNAL OF DESERT RESEARCH, 2011, 31(6): 1373-1379.

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