Acoustic Doppler velocimetry in aquaculture research: Raceway and quiescent zone hydrodynamics

Solids removal mechanisms in flow-through aquaculture systems generally consist of quiescent settling in a chamber followed by evacuation through a standpipe, vacuuming, filtering, and/or swirl separation. However, these methods are known to be time and labor intensive and are generally inefficient. Prior to attempting to design and model more efficient quiescent zones and solids removal systems, it is necessary to first establish baseline hydraulic operating characteristics in conventional systems. Acoustic Doppler velocimetry (ADV) is a relatively new technology used for the in situ measurement of three-dimensional velocities at discrete locations in flowing fluids, based on the Doppler Principle. In this study, hydrodynamic properties in a raceway system and quiescent zone were characterized using ADV technology and conclusions were developed, which are relevant to future improvements in overall operation and modifications to removal processes in raceways.