Escherichia coli bacteria use rotating helical flagella to swim. At this scale, viscous effects dominate inertia, and there are significant hydrodynamic interactions between nearby helices. These interactions cause the flagella to bundle during the "runs" of bacterial chemotaxis. Here we use slender-body theory to solve for the flow fields generated by rigid helices rotated by stationary motors...

E. coli bacteria swim following a run and tumble pattern. In the run state all flagella join in a single helical bundle that propels the cell body along approximately straight paths. When one or more flagellar motors reverse direction the bundle unwinds and the cell randomizes its orientation. This basic picture represents an idealization of a much more complex dynamical problem. Although it ha...

In this study an attempt has been made to study the hydrodynamic performance of pumpjet propulsor. Numerical investigation based on the Reynolds Averaged NavierStokes (RANS) computational fluid dynamics (CFD) method using structured grid, SST kω turbulence model has been carried out. The grid independence inspection is applied to verify accuracy of numerical simulation. The numerical prediction...

Drag and torque on nanobeads translating within the pericellular layer while attached to glycolipids of the plasma membrane are calculated by a novel hydrodynamic model. The model considers a bead that translates proximate to a rigid planar interface that separates two distinct Brinkman media. The hydrodynamic resistance is calculated numerically by a modified boundary integral equation formula...

This work gives an overview of the theoretical and experimental achievements of mechatronics applied to fluid film bearings. Compressible and uncompressible fluids are addressed. Rigid and elastic (deformable) bearing profiles are investigated. Hydraulic, pneumatic, magnetic and piezoelectric actuators are used. The ideas of combining control techniques, informatics with hydrodynamic, thermo-hy...

This paper examines the non-perturbed deposition and re-entrainment dynamics of biological and non-biological colloids in porous media in the presence of an energy barrier to deposition at the grain surface. Deposition and re-entrainment rate coefficients were determined from numerical simulation of breakthrough–elution behavior and the profiles of retained colloids. We present composite trends...

How anisotropic particles rotate and orient in a flow depends on the hydrodynamic torque they experience. The acting small spheroid uniform is computed by numerically solving Navier-Stokes equations. Overall, numerical results provide justification of recent theories for orientation statistics ice crystals settling cold clouds.

In this paper, we propose a series expansion of the baroclinic torque in low-Mach-number flows, so that accuracy and universality any buoyancy term could be examined analytically, new types terms constructed validated. We first demonstrate purpose introducing is to approximate torque, straightforwardly error defined with deviation its curl from corresponding torque. Then regular perturbation me...