Bioconvection in a phototactic algae suspension with oblique irradiation and forward anisotropic scattering

Abstract

In this study, we analyze the bioconvection in a suspension of phototactic algae that exhibits anisotropic scattering. The top layer of the suspension is illuminated by oblique collimated irradiation. During the study, the bottom boundary is considered as rigid whereas the top boundary is considered stress-free. In order to solve the eigenvalue problem, the Newton-Raphson-Kantorovich finite difference method of order four is used. Linear analysis of the basic state is performed using neutral curves. The results demonstrate a change in the most unstable mode from an overstable to a stationary state or vice versa for particular parameters in response to a variation in the incidence angle. The position of the maximum basic concentration shifts toward the top of the suspension as the incidence angle is increased. In most cases, the system becomes more unstable with an increment in the incidence angle.