It is important to measure the underwater bottom surfaces (e.g., scour depth for hydraulic structures). However, the equipments used in the laboratory and in the field are costly. As reported in literature, Kinect, a Microsoft video game device, can be used to capture the underwater bottom surfaces in a non-intrusive way. Several limitations for the Kinect have been documented. These are based on distance from the object, turbidity and illuminance. Correction procedures to obtain accurate object height are also provided for object in air and object inside water. This work focusses on the workability of Kinect in turbulent flow conditions. The turbulent flow condition is generated in a channel junction setup. An acoustic doppler velocimeter (ADV) is used to obtain the 3D velocity field. Turbulence characteristics (Turbulence intensity, Turbulent kinetic energy etc.) are computed from the velocity field. An object (oval shaped bowl) is positioned at different locations and is traced by the Kinect to measure its surface elevation. Results for the object (elevations in 3D space) obtained from the Kinect are compared with the true values. In addition to the refraction correction, correction for the turbulence is suggested. Finally, the procedure is demonstrated through measurement of a scour hole evolved due to steady flow in the channel junction.
.jpg "Pranab K. Mohapatra, PhD photo")
