TY - JOUR ID - 15793 TI - Study of the Bed Shear Stress Distribution around River Structures using Three Ports Preston Tube JO - Journal of Hydraulics JA - JHYD LA - en SN - 2345-4237 AU - Safarzadeh, Akbar AU - Salehi Neyshabouri, Seyed Ali Akbar AD - Assistant Professor, Faculty of Engineering, University of Mohaghegh Ardabili, Iran AD - Professor of Hydraulic Structures, WERI, Tarbiat Modares University, Tehran, Iran Y1 - 2012 PY - 2012 VL - 7 IS - 2 SP - 47 EP - 62 KW - Bed Shear Stress KW - Three Tube Instrument KW - Pressure Transducer KW - Groyne KW - Shear Layer DO - 10.30482/jhyd.2013.15793 N2 - In this paper available techniques of the bed shear stress measurement was reviewed and the three tube device, an efficient instrument with 85 Hz measuring frequency, was developed to measure the local bed shear stress around the river structures. The main advantage of the developed instrument is that it is not necessary to align the measuring ports in the local flow direction. Distribution of the bed shear stress around a single straight groyne in a flat and immovable bed has been measured using the three ports instrument. The maximum bed shear stress amplification at the groyne head, bed shear stress pattern along the outer side of the shear layer, distribution and general amplification and the zone where the scouring process initiates at the upstream of the groyne due to the general bed shear stress amplification were extracted. The measured data agrees well with the available experimental results and with the accurate numerical simulations as well. UR - https://jhyd.iha.ir/article_15793.html L1 - https://jhyd.iha.ir/article_15793_1044d85e64294964d1c47307861fc870.pdf ER -