title: Decrease in light/dark cycle of microalgal cells with computational fluid dynamics simulation to improve microalgal growth in a raceway pond.
abstract: In this study, computational fluid dynamics (CFD) was used to systemically analyze the movement of algae in a vortex flow field produced by up-down chute baffles. The average cell light/dark (L/D) cycle period, vertical fluid velocity, fraction of time the algae was resides in light zone and the L/D cycle period were investigated under different paddlewheel speeds and microalgal concentrations. Results showed that the L/D cycle period decreased but the vertical fluid velocity increased when the up-down chute baffles were used. The L/D cycle period decreased by 24% (from 5.1s to 3.9s), and vertical fluid velocity increased by 75% when up-down chute baffles were used with paddlewheel speed of 30r/min. The probability of L/D cycle period of 3s increased by 52% from 0.29 to 0.44 with the up-down chute baffles. This led to approximately 22% increase in biomass yield without changing the paddlewheel speed.
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Zongbo
authors: Z
authors: Yang
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China. Electronic address: juncheng@zju.edu.cn.
authors: Jun
authors: J
authors: Cheng
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Qing
authors: Q
authors: Ye
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Jianzhong
authors: J
authors: Liu
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Junhu
authors: J
authors: Zhou
authors: State Key Laboratory of Clean Energy Utilization, Zhejiang University, Hangzhou 310027, China.
authors: Kefa
authors: K
authors: Cen
mesh_terms: D018533:Biomass; D019295:Computational Biology; D057446:Hydrodynamics; D008027:Light; D058086:Microalgae / Q000254:growth & development* / Q000502:physiology; D017440:Photoperiod; D061005:Ponds / Q000382:microbiology*
keywords: Computational fluid dynamics; Flashing light; Microalgae; Raceway pond