vol. 10 núm. 2 (2019)

Several studies in microalgae cultures show the relation between the photosynthetic efficiency and agitation, this effect was evaluated in solar collectors for tubular photobioreactors, which have different geometries in cross section (circular, octagonal, hexagonal and square). In this work, a computational study of microalgae culture (single-phase flow) for each of these solar collectors with a hydraulic diameter of 2 in, 100 in of length and six different culture inlet velocities to the collector (0.25 to 0.5 m/s) are performed to set the influence of profiles on the fluid behavior. The speed, pressure drop, secondary flow and shear stress was analyzed, establishing that the collector with hexagonal profile provides better agitation due to the irregular geometry, but the inlet velocities of the culture must be used in the collector for less than 0.3 m/s to ensure a continuous growth model of microalgae according to the literature tendency. It was found, under this operation regime, that the shear stress values do not cause damage to the wall cell of the microalgae making this implementation feasible in pilot plants.