EFFECT OF BED ROUGHNESS DISTRIBUTION AND CHANNEL SLOPE ON RECTANGULAR FREE OVERFALL

Author

Abstract
In this paper, the free overfall in rectangular channel with a different slopes and bed rough distribution was studied. Bed roughness was made of wood allocated in three different cases: two, three and zigzag rows. The aim of this study is to obtain discharge equations for free overfall depending on brink depth and slope. Three empirical equations proposed for calculating discharge. These equations influenced by slope, channel bed roughness as well as method of roughness distribution. Three rows bed roughness having grater effect on these relationships at steeper slopes.
the average values of hc/he at smooth bed is greater by (4%) with respect to that for bed rough at two rows, by (19%) with respect to that for bed rough at zigzag rows and by (24%) with respect to that for bed rough at three rows, so that values for three rows rough and horizontal channel is greater by (4%) with respect to that for channel slope at (1/200) and by (14%) with respect to that for channel slope at (1/100).

Keywords


Volume 6, Issue 2
Spring 2013
Pages 115-123

  • Receive Date 01 June 2013
  • Revise Date 20 June 2013
  • Accept Date 25 June 2013