American Society of Civil Engineers


Application of Radio Frequency Tracers to Individual and Group Particle Displacement within a Laboratory


by T. J. Lauth, (Graduate Research Assistant, IIHR-Hydroscience and Engineering, Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, IA 52242, E-mail: timothy-lauth@uiowa.edu.) and A. N. Papanicolaou, (Associate Professor, Robert and Virginia Faculty Fellow in Engineering, IIHR-Hydroscience and Engineering, Department of Civil and Environmental Engineering, The University of Iowa, Iowa City, IA 52242, E-mail: apapanic@engineering.uiowa.edu.)
Section: Environmental Cyber-Sensing and Modeling II, pp. 2264-2271, (doi:  http://dx.doi.org/10.1061/41036(342)225)

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Document type: Conference Proceeding Paper
Part of: World Environmental and Water Resources Congress 2009: Great Rivers
Abstract: Multiple approaches (shear stress, discharge, stream power, etc.) have been developed for describing the rate of bedload movement, each with a means of being calculated in the field. One current approach relies on the mean virtual velocity of individual sediment particles. Virtual velocity is determined by dividing the displacement length of a particle by the sum of the rest and displacement times. The focus of this research is the application of a Radio Frequency Identification (RFID) system as a means to monitor individual and group particle displacement and rest times necessary for calculating the virtual velocity, so that the bedload transport rate can be predicted. An RFID system consists of programmed transponders and a corresponding reader that communicate using radio waves. This communication provides the ability to track individual particles with embedded transponders. By setting customized antennas in the flume to act as gateways, communication between the antennas and particles traveling over a known distance provides the time between antennas, allowing for the calculation of the 1-D virtual velocity. To develop this system, multiple obstacles needed to be overcome. Past RFID research has shown that transponder orientation and transponder signal collision can present large problems to the application of RFID technology to sediment transport research. These two problems have been accounted for by: 1) using particles consisting of two transponders oriented perpendicularly to each other, and by 2) using transponders that have anti-collision signal capabilities. The use of anti-collision capable transponders also provides the capability of tracking the flux of a group of particles. Tracking a group of particles allows for correction due to the flow field and the possibility of hiding. Cameras and image analysis tools will be used for confirmation of results.


ASCE Subject Headings:
Particles
Displacement
Bed loads
Velocity
Sediment