Document Type : Research Paper
Graduated Student of Water Engineering and Environment Faculty, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
Professor of Water Engineering and Environment Faculty, Shahid Chamran Univeristy of Ahvaz,Ahvaz, Iran.
Obstacles such as piers of a bridge inflow confuse and disturb its natural form. With passing the flow through these obstacle disturbances create downstream, called the Von Karman Street vortex shedding. When the frequency of the microwaves is equal to the natural frequency of the current approach, the resonance will form. If the flow walls are constant such as a flume, this phenomenon may see as a transversal wave. Actual examples of this phenomenon created near the bridge piers in a canal called the Delta Mendota, as well as in the New York canal around the I-84 Bridge (Schuster, 1967).
Numerous people in this field have done research that mostly with variables such as channel width, shape, and placement of obstacles in the channel to study different wave characteristics, including its amplitude and frequency. Zima, L., and Ackermann (2002), Ghomeshi et al. (2007), Jafari et al. (2010), Meile et al. (2011), and Sarkar (2012) tried to find the maximum amplitude of the created wave by using obstacles with different diameters. Zhao et a. (2014) performed their experiments to measure the coefficient and tensile force created in the vicinity of obstacles while transmitting transverse waves. This study aimed to find a relationship between the percentage of obstacle immersion and wave characteristics.