We calculate the average hydrodynamic stress on fractal aggregates of spheres using Stokesian dynamics. We find that for fractal aggregates of force-free particles, the stress does not grow as the cube of the radius of gyration, but rather as the number of particles in the aggregate. This behavior is only found for random aggregates of force-free particles held together by hydrodynamic lubricat...

Animal cells are affected by hydrodynamic forces that occur in culture vessel, transfer piping, and recovery operations such as microfiltration. Depending on the type, intensity, and duration of the force, and the specifics of the cell, the force may induce various kinds of responses in the subject cells. Both biochemical and physiological responses are observed, including apoptosis and purely ...

Three-dimensional unsteady computations of the flow past a flapping and deforming fin are performed. The computed unsteady lift and thrust force time histories are validated with experimental data and are in good agreement. Several fin parametric studies are performed for a notional Unmanned Underwater Vehicle (UUV). The parametric studies investigated the force production of the fin as a funct...

Dynamic force measurements have been made between an oil drop and a silica particle in surfactant and sucrose solutions with viscosities that range up to 50 times that of water. These conditions provide variations in the shear rate and the relative time scales of droplet deformation and hydrodynamic drainage in a soft matter system. The results obtained indicate that soft deformable boundaries ...

A model that has been shown to give very accurate predictions of dynamic forces between deformable emulsion drops and bubbles is used to quantify the effects of internal flow and viscosity ratio on the hydrodynamic interaction in such systems. The results demonstrate that direct force measurement using an atomic force microscope can readily differentiate whether the interfaces of drops of diffe...

The median fins of fishes consist of the dorsal, anal, and caudal fins and have long been thought to play an important role in generating locomotor force during both steady swimming and maneuvering. But the orientations and magnitudes of these forces, the mechanisms by which they are generated, and how fish modulate median fin forces have remained largely unknown until the recent advent of Digi...

In the present work, the motion of metallic and plastic particles of 5 mm diameter falling in a quiescent fluid is investigated experimentally. The goal of this investigation is to examine the effect of history force acting on a particle in a range of Reynolds numbers between 1000 and 5000. The instantaneous position of the particle was recorded using a high - speed camera (500 to 1000 frames p...

The contribution to the fieldionospheric F region and sources of the heavy ions aligned ionospheric ion momentum equation, due to which are accelerated to several electron volts at coupling between pressure anisotropy and the greater altitudes and subsequently flow from the inhomogeneous geomagnetic field, is investigated. ionosphere into the magnetosphere. In order to We term this contribution...

Estimation of natural frequency of structures is very important and isn’t usually calculated simply and sometimes complicated. Lack of knowledge about that caused hard damage and hazardous effects. In this paper, with using from two different models in FEM method and based on hydrodynamic mass of fluids, natural frequency of an especial bearing (Fig. 1) in an electric field (or, a periodic forc...