We study the stochastic motion of a Brownian particle driven by a constant force over a static periodic potential. We show that both the effective diffusion and the effective drag coefficient are mathematically well-defined and we derive analytic expressions for these two quantities. We then investigate the asymptotic behaviors of the effective diffusion and the effective drag coefficient, resp...

It is important to reveal the relations of physical factors to deposition of contaminants on insulator. In this paper, the simulation model of high voltage end of insulator was established to study the force and motion characteristics of particles affected by electric force and airflow drag force near the ultra-high voltage direct current (UHVDC) insulator. By finite element method, the electri...

The plasma force on grains of specified charge and height in a collisional DC plasma sheath are calculated using the multidimensional particle in cell code COPTIC. The background ion velocity distribution functions for the unperturbed sheath vary substantially with collisionality. The grain force is found to agree quite well with a combination of background electric field force plus ion drag fo...

Exact analytical solutions are found for the steady state creeping flow in and around a vapor-liquid compound droplet, consisting of two orthogonally intersecting spheres of arbitrary radii (a and b), submerged in axisymmetric extensional and paraboloidal flows of fluid with viscosity μ. The solutions are presented in singularity form with the images located at three points: the two centers of ...

Plants growing in rivers and lakes experience drag forces imposed by flowing water. In order to reduce the drag, plants reconfigure and streamline themselves at multiple scales. The ability of plants to reconfigure depends on their morphological and bio-mechanical properties. The plant leaves play an important role in this process which is still to be better defined and quantified. Therefore, t...

We present the results of an investigation of the drag force on a horizontal grid of bars moving vertically through a stratified fluid. A novel approach was used to calculate the drag, based on measurements of the terminal velocity of a freely rising grid. In the homogeneous case the drag coefficient of the grid is found to be approximately constant for a range of grid-based Reynolds numbers. I...

The AdS/CFT correspondence and a classical test string approximation are used to calculate the drag force on an external quark moving in a thermal plasma of N = 4 superYang-Mills theory. This computation is motivated by the phenomenon of jet-quenching in relativistic heavy ion collisions.

in this paper, the interactions of flow over two circular or rectangular cylinders, passing by each other, have been investigated, using overset grids method. two-dimensional incompressible governing fluid flow equations are solved using finite volume method. in this research, several interpolation methods have been tested to transfer data between grids. one of them called mass flux base interp...

The plunging of a large intruder sphere into a prefluidized granular bed with various constant velocities and various sphere diameters is investigated using a state-of-the-art hybrid discrete particle and immersed boundary method, in which both the gas-induced drag force and the contact force exerted on the intruder can be investigated separately. We investigate low velocities, where velocity d...