A level set approach for computation of bubble dynamics in airlift reactors.

In this work, we employ the so-called level set approach to simulate the rising of gas bubbles in a pilot-scale external loop airlift photobioreactor in which microalgae are used to capture CO2from flue gas and to treat wastewater. A coupled level set and finite difference method is adopted in this work to track the moving gas-liquid interfaces in the ALR riser. Level set methods implicitly represent dynamic fronts by solving an Hamilton-Jacobi partial differential equation such as the normal flow equation, in turn dependent on a flow function that can be regarded as a speed vector field. This latter, for the case at hand, is obtained by solving the non-dimensional Navier-Stokes equations through a Chorin type projection technique on a staggered grid