摘要
当流动的床面由松散的颗粒层组成时,由于在颗粒层中存在着孔隙,水流能够渗透到孔隙中去,并在主流带动下沿孔隙通道流动.孔隙流的存在,破坏了一般的床面流动壁面上流速为零的无滑动条件,从而改变了整个水流的流动结构,影响到河道中水流的流速分布和阻力规律.本文根据输沙试验中观察到的物理现象,建立了这种流动的物理图形,并从理论上分析了这类流动的规律,得到了孔状可渗床面流动的速度分布和阻力计算公式,最后用实验资料对所得成果进行了初步验证.研究成果不仅对改进冲积河流阻力计算有重要作用,对于类似床面的流动规律研究也有参考价值.
If a channel bed consists of loose grains,water can permeate through holes among the grains and can flow along with the main flow.The no-slip condition at solid boundary is not satisfied,thereby the flow structure will be greatly changed,in this paper,based on the physical phenomena observed in flume experiments and theoretical analysis of the law of flow,Some formulae of velocity distribution and resistance for flow on porous permeable bed are obtained,and they are verified with some experimental data.The results obtained are of importance to flow resistance calculation for fluvial rivers,and also to flow analysis for similar beds.
出处
《河海大学学报（自然科学版）》
CAS
CSCD
1993年第4期38-44,共7页
Journal of Hohai University(Natural Sciences)
关键词
孔状可渗床面
流速
分布
porous permeable bed
flow through holes among grains
velocity distribution
resistance law of flow
