Experimental Comparison of Variations in Water Level, Reynolds Shear Stress, and Flow Velocity Collected by Using ADV and PIV Around Undamaged and Damaged Piers during Generation of Positive Surges in Sloped and Horizontal Channels
Subject Areas : Article frome a thesisEhsan Oveici 1 , Omid Tayari 2 , Navid Jalalkamali 3
1 - Ph.D. Graduate Student, Department of Civil Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran
2 - Assistant Professor, Department of Civil Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran
3 - Assistant Professor, Department of Water Engineering, Kerman Branch, Islamic Azad University, Kerman, Iran
Keywords: Experimental Model, Bridge pier, Particle Image Velocimetry, Acoustic Doppler velocimetry, Positive surge,
Abstract :
The presence of positive surges can cause bank destruction, bed scouring, and damages to structures such as bridge piers installed on the path. On the other hand, the remains and bridge pier destruction waste on the path affect velocity variations and flow surface fluctuations resulting from these surges and require careful investigations. This study comprises an experimental analysis of the effect of present damaged and undamaged bridge piers on flow pattern variations during the generation of positive surges in sloped and horizontal channels. To this aim, ADV was utilized to help collect three-dimensional flow velocity data. Moreover, PIV was used to help make a comparison with ADV data results. Four distinct probes were incorporated for bathymetry in the horizontal and the sloped channels. The obtained results were indicative of non-breaking undular surges generated in the horizontal channel and non-breaking and breaking undular surges formed in the sloped channel. In the sloped channel, the maximum velocity increase occurred with installation of two piers, which showed a 34.39% increase compared to that under the same conditions in the horizontal channel. Furthermore, the average water level variations due to the slope of the channel in cases without an element, with a damaged element, with an undamaged element, and with a combination of damaged and undamaged elements were respectively equal to 31.66, 32.70, 29.88, and 27.40%. In addition, the Reynolds shear stress values were also calculated in the sloped channel to be 7.6, 3.57, 1.38, and 1.68 times those in the horizontal channel.