A novel mixer was developed to improve the performance of flat-plate photobioreactors (PBRs). The
effects of mixer were theoretically evaluated using computational fluid dynamics (CFD) according to
radial velocity of fluid and light/dark cycles within reactors. The structure parameters, including the riser
width, top clearance, clearance between the baffles and walls, and number of the chambers were further
optimized. The microalgae culture test aiming at validating the simulated results was conducted indoor.
The results showed the maximum biomass concentrations in the optimized and archetype reactors were
32.8% (0.89 g L1) and 19.4% (0.80 g L1) higher than that in the control reactor (0.67 g L1). Therefore, the
novel mixer can significantly increase the fluid velocity along the light attenuation and light/dark cycles,
thus further increased the maximum biomass concentration. The PBRs with novel mixers are greatly
applicable for high-efficiency cultivation of microalgae.