Façades, Innovation, Sustainability
Algae cultures are excellent repositories for storing solar thermal energy. Cultivation of algae for use as a renewable energy source is a promising up-and-coming technology.
The aim of the FABIG (‘façades with glass bioreactors’) project is the design and construction of façade-integrated photobioreactors for algae cultivation, which Arup is developing together with project partners. The success of the technology will depend on the efficiency of the reactors, which will also play a decisive role in their market acceptance. In this study, reactor efficiency has been improved using detailed multiphase flow simulations conducted using the open-source computational fluid dynamics (CFD) toolbox OpenFOAM®.
The research resulted in improvement of the design details of photobioreactors and an increase in the productivity of algae cultivation in façade-integrated reactors.
We also improved our skills in multiphase flow simulation within the CFD toolbox OpenFOAM®. A mesh creation script for flexible variation of the simulated reactor geometry was developed.
Evaluation tools to analyse the air phase fraction, pressure and flow velocity in the algae suspension and to quantify the effect on the productivity of the photobioreactor were developed.
CFD simulations can be used to investigate different geometries and configurations of photobioreactor and the effects on optimal algae growth conditions, to improve the efficiency of designed systems. The CFD simulations include evaluation of the dynamic pressure profile due to airlift mixing, which is an essential input for the design and construction of the glass panels.
This work has demonstrated the usefulness of CFD modelling and simulation of multiphase flow particularly with regard to optimization of photobioreactor geometry. Use of modelling increased productivity through optimization of the photobioreactor geometry: this is important as improvements in photobioreactor efficiency will help make this technology competitive.