沙波迎流面泥沙起动流速研究  

Incipient velocity of sediment on the forward slope of dunes

作　　者：马殿光[1] 董伟良[2] 徐俊锋[1] 乐培九[1] 

机构地区：[1]交通运输部天津水运工程科学研究院,天津300456 [2]河海大学港口海岸与近海工程学院,江苏南京210098

出　　处：《泥沙研究》2016年第2期46-51,共6页Journal of Sediment Research

基　　金：中央级公益性科研院所基本科研业务费专项(TKS130105;TKS150102)

摘　　要：利用概化沙波模型,研究了不同坡度、粒径及位置情况下的泥沙起动流速,根据实测数据指出沙波泥沙起动流速特征,并分析比较了与平坡起动的差别。通过对泥沙颗粒的受力分析,提出水流冲击力,并利用沙波垂线流速分布公式进行流速换算,建立了沙波泥沙起动流速计算公式。结果表明:在相同水流条件下,因沙波地形影响,迎流面泥沙起动流速值小于平坡;沙波不同位置处的泥沙起动流速非定值,随着水平位置而变化;坡度和粒径对再附点附近泥沙起动流速影响较小。通过验证比较表明,公式计算结果与实测资料基本一致,适用于描述沙波迎流面泥沙起动规律,可反映出沙波坡度和水平位置的影响。Experimental study was conducted over four asymmetric dunes with a 4m crest length, two crest heights （0. 3m,0. 4m）, and two uniform sediment with mean grain sizes Ds0 = 0. 5 and 0. 7 mm. By using Acoustic Doppler Velocimeter （ADV）, the incipient velocities were measured, and the differences of velocity over dunes and flat surface bed are analyzed. Based on the method considering the incipient motion of sediment particles over dunes, a theoretic formula is derived with impulse force of flow and the velocity distribution formu- la for dunes. Results show that the incipient velocity affected by slope is less than the flat bed, which changes with the horizontal position. Particle size and slope had less influence on the incipient velocity of sediment near the reattachment point. It is tested by experimental data that the theoretical results are agree with the measured, showing the influence of slope and the horizontal position on the incipient motion of sediment particles over dunes.

关 键 词：沙波 无黏性沙 起动流速 坡度 水平位置 

分 类 号：TV142.1[水利工程—水力学及河流动力学]