Jordan Journal of Civil Engineering

Paper Detail

A Laboratory Study on Stilling Basin with Semicircular Rough Bed Elements

Volume 11, No. 2, 2017
Received: 2017/03/06, Accepted:


Ali Mohsen Hayder;


In this research, a laboratory study of hydraulic jump properties was conducted by making small semicircular rough elements, which covered the stilling basin floor downstream of spillway. The objective of this research was to introduce and make a comparison of roughed bed hydraulic jump stilling basin by using semicircular rough elements. To reach such an idea, a new expression was first developed for sequent depth and hydraulic jump length. Then, hydraulic jumps were conducted on a bed of prismatic roughness elements in a rectangular flume in order to investigate the jump effect on the characteristics of stilling basin. The rough elements are positioned on the bed of the flume downstream of an Ogee spillway in such a way that the incoming water jet is just skimming above the elements’ top surface. Each rough element shape was tested under different Froude numbers, ranging from 4 to 11. In each test, the water surface profile, the roller length and the jump length were measured. The experimental results showed that the presence of a rough element increases the shear force and consequently reduces the jump length and the sequent depth of flow. Comparison of the results with those of previous studies showed that using beds roughed with semicircular shaped elements can decrease the length of the stilling basin by 56% of any regular basin and the sequent depth of the jump by 25% of a comparable one occurring on a smooth bed. Also, the average value of energy dissipation was computed and found to range between 68.1% and 60.4% of stilling basin of type I developed by Peterka (1978).


Stilling basin, Hydraulic jump, Semicircular rough bed elements