雨水口箅子的孔口流量系数试验研究

Experiment on Discharge Coefficients for Orifices of Gutter Grates

孔口流量系数大小对雨水口箅子的泄流能力具有重要影响。对等格条间距和等格条厚度的矩形断面横条箅子和圆形断面横格条箅子的孔口流量系数进行了试验研究,结果表明雨水口箅宽方向截留纵坡向来水时,随来水量增大,矩形断面格条箅子的流量系数呈略减小趋势,其流量系数比圆形断面格条箅子稳定;雨水口泄流箅上深度积水时,矩形断面格条箅子的流量系数明显小于圆形断面格条箅子。该结果可对雨水口箅子的选用和雨水口的设计计算具有重要参考意义。

Discharge coefficient for orifices has an important influence on the discharge capacity of gutter grates .Experi-ments were conducted to research discharge coefficients for two kinds of gutter grates .The horizontal lattice bars in both gutter grates were designed with equal distance and equal thickness ,of which one was rectangular cross section ,and the other was circular section .The experiment result showed that when the flow was intercepted by rain grating along the width of grating ,the discharge coefficient of rectangular lattice bar grate slightly decreased with the increase of water inlet along longitudinal slope .And its coefficient was more stable than that of the circular section lattice bar grate .Besides , discharge coefficient of the former was markedly smaller than that of the latter when there was a large amount of seeper to discharge .The results can provide reference for the selection of gutter grates and the design calculation of the orifices of the grates .