Cost-effective implementation of microalgae as a solar-to-chemical energy conversion platform requires extensive system optimization; computer modeling can bring this to bear. This work uses modified versions of the U.S. Environmental Protection Agency's (EPA's) Environmental Fluid Dynamics Code (EFDC) in conjunction with the U.S. Army Corp of Engineers' water-quality code (CE-QUAL) to simulate hydrodynamics coupled to growth kinetics of algae (Phaeodactylum tricornutum) in open-channel raceways. The model allows the flexibility to manipulate a host of variables associated with raceway-design, algal-growth, water-quality, hydrodynamic, and atmospheric conditions. The model provides realistic results wherein growth rates follow the diurnal fluctuation of solar irradiation and temperature. The greatest benefit that numerical simulation of the flow system offers is the ability to design the raceway before construction, saving considerable cost and time. Moreover, experiment operators can evaluate the impacts of various changes to system conditions (e.g., depth, temperature, flow speeds) without risking the algal biomass under study.

Experiments were conducted to measure the performance of direct-current-pulsed electrohydrodynamic drop formation as a function of liquid viscosity, electrical conductivity, and surface tension. While hydrodynamic and charge relaxation times and Taylor cone formation frequencies suggest theoretical drop-generation frequencies well in excess of 100 Hz, we show that it is impossible to produce more than 50 drops per second with performance decreasing as viscosity increased or electrical conductivity decreased (and not a significant function of surface tension). Instead of relying on relaxation-time calculations to predict the maximum, reliable drop-production frequency, a dimensionless coefficient that is a function of viscosity and electrical conductivity is proposed to estimate the fulcrum frequency.