Ecohydraulic Flow Sensing and Classification Using a Lateral Line Probe

Natural flows are a complex amalgam of velocity, pressure, and vorticity, which often cannot be directly measured or simulated due to their physical interdependence and scaling. Ecohydraulic investigations require not only an accurate description of the natural flow, but must also consider the fluid-body interactions between the indicator organism and the surrounding flow field. In this work, we show how a fish-shaped lateral line probe (LLP) can be used for in situ flow sensing, including fluid-body interactions in a laboratory scale vertical slot fish pass. The LLP consists of a synchronous collocated sensor array with 16 pressure sensors measuring at 2.5 kHz with an acquisition frequency of 250 Hz. Using a signal processing workflow with time-domain features based on the Bernoulli equation, the multi-sensor fusion capabilities of the device can be leveraged to provide current velocity estimates similar to conventional measuring devices such as acoustic Doppler velocimeters (ADVs). Finally, it is shown that the LLP can be used for spatial flow signature clustering and classification using semantic inputs in conjunction with supervised learning algorithms. Our objective is to introduce the LLP as a new type of ecohydraulic flow measurement and classification device to simplify the evaluation of natural flows and expanding the analytical capabilities of ecohydraulic investigations.