Shear stresses are produced when a fluid is flowing along a solid boundary layer. Shear stress measurements can be used to evaluate sediment and soil erosion transportation in natural bodies of water, like rivers. With this information, engineers improve risk assessment evaluation on earthen water- retaining structures and mitigate the dangers of overtopping.
Inside the COAS Wave Lab water tank, a flume was built with a 5% slope, simulating a riverbed at an angle. At the 20ft marker, three shear stress sensors were installed in a working envelope. AC Drivers were used to control the flow from four pumps that provided the water flow on the wall shear sensors. The experiment data is collected using a LabView code and then processed in a MATLAB code that provides graphs and CSV files. A magnetic flowmeter and Micro PIV read by a laser and highspeed camera are used to collect velocity data on the velocity of the flow and compare it with the information gathered on the shear sensors. Multiple tests have been conducted to collect the best sample data sets from the experiment.
A successful data sets will be used to create a Computational Fluid Dynamics (CFD) model using COMSOL Multiphysics. This model will demonstrate the flow velocity and wall shear stress ranges at a given flow rate, variable turbulence and roughness of the boundary layers
