Bio-inspired particle separator design based on the food retention mechanism by suspension-feeding fish.

A new particle separator is designed using a crossflow filtration mechanism inspired by suspension-feeding fish in this study. To construct the model of the bio-inspired particle separator, computational fluid dynamics techniques are used, and parameters related to separator shape, fluid flow and particle properties that might affect the performance in removing particles from the flow, are varied and tested. The goal is to induce a flow rotation which enhances the separation of particles from the flow, reduce the particle-laden flow that exits via a collection zone at the lower/posterior end of the separator, while at the same time increase the concentration of particles in that flow.

The benefits of planar circular mouths on suction feeding performance.

Suction feeding is the most common form of prey capture across aquatic feeding vertebrates and many adaptations that enhance efficiency and performance are expected. Many suction feeders have mechanisms that allow the mouth to form a planar and near-circular opening that is believed to have beneficial hydrodynamic effects. We explore the effects of the flattened and circular mouth opening through computational fluid dynamics simulations that allow comparisons with other mouth profiles.

Computational fluid dynamics of fish gill rakers during crossflow filtration.

We study crossflow filtration mechanisms in suspension-feeding fishes using computational fluid dynamics to model fluid flow and food particle movement in the vicinity of the gill rakers. During industrial and biological crossflow filtration, particles are retained when they remain suspended in the mainstream flow traveling across the filter surface rather than traveling perpendicularly to the filter. Here we identify physical parameters and hydrodynamic processes that determine food particle movement and retention inside the fish oral cavity.

Use of computational fluid dynamics to study forces exerted on prey by aquatic suction feeders.

Suction feeding is the most commonly used mechanism of prey capture among aquatic vertebrates. Most previous models of the fluid flow caused by suction feeders involve making several untested assumptions. In this paper, a Chimera overset grids approach is used to solve the governing equations of fluid dynamics in order to investigate the assumptions that prey do not interact with the flow and that the flow can be modelled as a one-dimensional flow.

Modeling the hydraulics of root growth in three dimensions with phloem water sources.

Primary growth is characterized by cell expansion facilitated by water uptake generating hydrostatic (turgor) pressure to inflate the cell, stretching the rigid cell walls. The multiple source theory of root growth hypothesizes that root growth involves transport of water both from the soil surrounding the growth zone and from the mature tissue higher in the root via phloem and protophloem. Here, protophloem water sources are used as boundary conditions in a classical, three-dimensional model of growth-sustaining water potentials in primary roots.

Computational fluid dynamics within bifurcated abdominal aortic stent-grafts.

Purpose: To assess the hemodynamic forces on a bifurcated abdominal aortic stent-graft under realistic conditions of flow, blood pressure, and sac pressure.

Methods: Computational fluid dynamics was used to study the temporal and spatial variations in surface pressure and shear through the cardiac cycle on models of bifurcated stent-grafts derived from computed tomography in 4 patients who had previously undergone endovascular repair of abdominal aortic aneurysm (AAA). The trunk, bifurcation, and limbs of the graft were analyzed separately and as parts of a unified whole.

Spatial and temporal patterns of water flow generated by suction-feeding bluegill sunfish Lepomis macrochirus resolved by Particle Image Velocimetry.

The suction-feeding fish generates a flow field external to its head in order to draw prey into the mouth. To date there are very few empirical measurements that characterize the fluid mechanics of suction feeding, particularly the temporal and spatial patterns of water velocity in front of the fish. To characterize the flow in front of suction-feeding bluegill sunfish Lepomis macrochirus, measurements with high spatial (<1 mm) and temporal (500 Hz) resolution were taken using Particle Image Velocimetry (PIV).