Effects of different bed roughnesses on the characteristics of hydraulic jumps

Download
2012
Velioğlu, Deniz
In practice, baffle blocks and sills are commonly being used to stabilize the location of a hydraulic jump and shorten the length of a stilling basin. On the other hand, gravels, corrugations and rectangular prismatic roughnesses which cover the entire length of the basin or placed in a staggered manner may be an alternative. The objective of this study is to determine the effects of these roughness elements on the characteristics of hydraulic jumps such as conjugate depth, jump length and energy dissipation using experimental data collected from the previous studies. The investigations show that the roughness elements have positive effects on the characteristics of hydraulic jumps. The tailwater depth reduction compared to classical jump is 2-10%. The length of the jump is reduced about by 30-50% by prismatic roughness elements, 40% by corrugations, and 30% by gravels. The roughness elements induce 3-15% more energy dissipation than that of classical jump. Therefore, these types of bed roughness elements should be considered as an effective alternative of accessory devices such as baffle blocks and sills.

Suggestions

A NUMERICAL AND EXPERIMENTAL STUDY ON THE CHARACTERISTICS OF HYDRAULIC JUMPS ON ROUGH BEDS
Velioglu, Deniz; Tokyay, Nuray; Dincer, Ali Ersin (2015-07-03)
Baffle blocks and sills are common accessory devices which are used in order to stabilize the location of a hydraulic jump and shorten the length of a stilling basin. On the other hand, strip roughness elements which cover the entire length of a basin may be an alternative. The objective of this study is to determine the effects of this type of roughness elements on the characteristics of hydraulic jumps such as conjugate depth ratio, jump length and energy dissipation. The study is carried out using experi...
Forced hydraulic jump on non-protruding rough beds
Tokyay, Nuray; Simsek, C. (2011-10-01)
Baffle blocks and sills are commonly used to stabilize the location of a hydraulic jump and shorten its length. However, corrugations or prismatic roughness elements may be effective alternatives to them. In the present study, experiments were performed to determine the effects of corrugations and prismatic roughness elements on fundamental characteristics of jump such as length, tailwater depth, and energy dissipation capacity. Corrugations were placed to cover the entire length of the basin. Prismatic rou...
Effect of prismatic roughness on hydraulic jump in trapezoidal channels
Evcimen, Taylan Ulaş; Tokyay, Nuran; Department of Civil Engineering (2012)
A study of the hydraulic jump on a trapezoidal prismatic channel and roughened beds is presented. Extensive measurements have been made regarding the characteristics of hydraulic jumps as sequent depths, wing fluctuations, energy dissipation and jump length on artificially roughened beds for Froude numbers between 4.16 and 14.58. Three different types of prismatic roughness elements and nine different roughness patterns were installed separately on channel bottom and side walls throughout the experiments to...
The effect of prismatic ruoghness elements on hydraulic jump
Evcimen, Taylan Ulaş; Tokyay, Nuray; Department of Civil Engineering (2005)
The objective of this study is to determine the effect of different roughness types and arrangements on hydraulic jump characteristics in a rectangular channel. Three different types of roughness were used along experiments. All of them had rectangular prism shapes and that were placed normal to the flow direction. To avoid cavitation, height of roughness elements were arranged according to level of the channel inlet, so that the crests of roughness elements would not be protruding into the flow. The effect...
Effect of Channel Bed Corrugations on Hydraulic Jump
Tokyay, Nuray (2005-05-15)
There have been many investigations on the effect of roughness elements on physical parameters of hydraulic jump. In practice, baffle blocks and sills are commonly being used to stabilize the location of a jump and shorten the length of a stilling basin. On the other hand, corrugations which cover the entire length of the basin may be an alternative. In the present study, hydraulic jumps on corrugated channel beds are studied experimentally. Values of 0.20 and 0.26 were used as the wave steepness of corruga...
Citation Formats
D. Velioğlu, “Effects of different bed roughnesses on the characteristics of hydraulic jumps,” M.S. - Master of Science, Middle East Technical University, 2012.