Hydrodynamic analysis of flow in raceway ponds for algae cultivation under versatile conditions

Abstract

Open looped channels are an energy-efficient and low-cost solution often adopted for the cultivation of algae. These channels are commonly composed by two parallel straight channels interconnected by two curving sections and, as such, are referred as raceway ponds. The scaling up of algae production systems, usually associated with novel usages of algal products, has created new challenges for raceway-based cultivation systems. In particular, the uncertainties of cultivating novel algae cultures, e.g. macroalgae for which optimal inland cultivation conditions are still under-researched, impose further demands for raceway design and operation. Versatile operational conditions for raceways may be thus desirable for pioneering inland cultivation systems for certain species, applications and climate conditions. In this work, raceways of standard design are evaluated in terms of geometry, specifically raceway length, width and operational conditions, i.e. flow depth and operational velocity, with the use of a CFD tool. The hydrodynamic performance of the studied cases is analysed based on velocity uniformity and power consumption.