Installation of flow deflectors and wing baffles to reduce dead zone and enhance flashing light effect in an open raceway pond

• A novel raceway pond with flow deflectors and wing baffles was developed.
• Pressure loss and dead zone decreased with flow deflectors.
• Period of average L/D cycle was significantly shortened with wing baffles.
• Biomass concentration in the novel raceway pond increased by 30.11%.

To reduce the dead zone and enhance the flashing light effect, a novel open raceway pond with flow deflectors and wing baffles was developed. The hydrodynamics and light characteristics in the novel open raceway pond were investigated using computational fluid dynamics. Results showed that, compared with the control pond, pressure loss in the flow channel of the pond with optimized flow deflectors decreased by 14.58%, average fluid velocity increased by 26.89% and dead zone decreased by 60.42%. With wing baffles built into the raceway pond, significant swirling flow was produced. Moreover, the period of average L/D cycle was shortened. In outdoor cultivation of freshwater Chlorella sp., the biomass concentration of Chlorella sp. cultivated in the raceway pond with wing baffles was 30.11% higher than that of the control pond.