3,183 research outputs found
Effect of rotation on anisotropic scattering suspension of phototactic algae
In this article, the effect of rotation on the onset of phototactic
bioconvection is investigated using linear stability theory for a suspension of
forward-scattering phototactic algae in this article. The suspension is
uniformly illuminated by collimated flux. The bio-convective instability is
characterized by an unstable mode of disturbance that transitions from a
stationary (overstable) to an overstable (stationary) state as the Taylor
number varies under fixed parameters. It is also observed that the suspension
has significant stabilizing effect due to rotation of the system
Effect of forward scattering and rigid top surface on the onset of phototactic bioconvection in an algal suspension illuminated by both oblique collimated and diffuse irradiation
The effect of the rigid top surface on the onset of phototactic bioconvection
is investigated using linear stability theory for a suspension of
forward-scattering phototactic algae in this article. The suspension is
uniformly illuminated by both diffuse and oblique collimated flux. The nature
of disturbance of bio-convective instability transits from a stationary
(overstable) to an overstable (stationary) state as the forward scattering
coefficient varies under fixed parameters. In presence of rigid top surface,
the suspension becomes more stable as the forward scattering coefficient
increases
Phototactic bioconvection with the effect of oblique collimated flux at forward scattering algae suspension in rotating medium
The primary objective of this article is to explore how rotation influences
the initiation of phototactic bioconvection. This investigation is conducted
through the application of linear stability theory to a suspension composed of
forward-scattering phototactic algae. The suspension is uniformly exposed to
oblique collimated flux. The bioconvection phenomenon is characterized by an
unstable disturbance mode that undergoes a transition from a stationary state
to an oscillatory state as the Taylor number varies while keeping other
parameters constant. Additionally, it is noteworthy that rotation of the system
has a substantial stabilizing effect on the suspension
Rotation and Oblique Irradiation Effects on Phototactic Algal Suspension Instability
In this study, we aim to explore the behavior of microorganisms in response
to natural lighting conditions, considering the off-normal angles at which the
sun strikes the Earth's surface. To achieve this, we investigate the effect of
oblique irradiation on a rotating medium, as this combination represents a more
realistic scenario in the natural environment. Our primary focus is on
understanding the phototactic behavior of microorganisms, which refers to their
movement towards or away from light. Under conditions of low light,
microorganisms tend to exhibit positive phototaxis, moving towards the light
source, while in intense light, they display negative phototaxis, moving away
from the light source. By studying a suspension that is illuminated by oblique
collimated flux with a constant radiation intensity applied to the top surface,
we can gain insights into how microorganisms respond to varying light
conditions and rotation. The stability analysis is conducted using linear
perturbation theory, which allows us to predict both the stationary and
oscillatory characteristics of the bio-convective instability at the onset of
bioconvection. Through this analysis, we observe that rotation plays a
significant stabilizing role in the system, while oblique irradiation has a
destabilizing effect on the suspension.Comment: arXiv admin note: substantial text overlap with arXiv:2306.1447
A combined effect of rigid top surface with diffuse and oblique collimated irradiation on the stability of the suspension of phototactic microorganisms
This article explores how a rigid top surface with diffuse and oblique
collimated irradiation affect isotropic scattering algal suspensions. When the
fluid flow becomes zero, the suspension reaches a steady (basic) state where
up-and-down swimming occurs due to interplay of phototaxis and diffusion. For
purely scattering suspensions, a bimodal steady state occurs due to scattering,
which reverts to a unimodal steady state as the angle of incidence increases
with fixed other governing parameters. To check the linear stability of the
suspension, a small perturbation to the basic state are considered and the
perturbed equations are solved by using the Newton-Raphson-Kantorovich (NRK)
iterative method. The linear stability of the same suspension predicts both
stable and oscillatory nature of disturbance for specific parameter ranges. A
rigid top surface, as well as diffuse and oblique collimated irradiation, make
the suspension more stable.Comment: 30 pages, 12 figures. arXiv admin note: text overlap with
arXiv:2302.1092
- …