Constrained Brownian Motion of a Single Ellipsoid in a Narrow Channel

Abstract

In this article, we explore the heat transfer of non-Newtonian liquid food in the heating process in a channel connecting a tank. To achieve a rapid heat diffusion, several cylindrical agitators are inserted into the tank. We pay special attention to a Chinese traditional food, i.e. the black sesame paste, which is predicted by the powerlaw model. The fluid flow and heat transfer are investigated numerically, under the impacts of the angular velocity of cylinder, the stirrer size and the rotational direction. Three different settings are investigated: the two-stirrer, the three-stirrer, and the 2 × 2 stirrer settings. Several applicable strategies could be applied to improve the heat transfer in food engineering practices, including changing the size, the rotational velocity, the direction, and the number of stirrers in the heat exchanger.

Dramatic change of the self-diffusions of colloidal ellipsoids by hydrodynamic interactions in narrow channels*

“…As mentioned in Ref. [19], the ellipsoids in our experimental system are strongly confined in the channel, which leads to a small angle (≤ 8 ∘ ) between their long axis and Xaxis, indicating that the ellipsoid is almost parallel to the Xaxis. Consequently, the long-axis of ellipsoids in our simulation is fixed along the channel.…”

“…According to Ref. [19], a larger ellipsoid has a lower diffusion coefficient in this case, which explains why D S < D S0 when X is small. Finally, we find that a more anisotropic ellipsoid induces a stronger flow in a longer range, which explains the larger X and stronger HIs for larger p in Fig.…”

“…, where D S0 is the diffusion coefficient of an isolated ellipsoid in the channel measured by experiment, and D ′ S0 is the diffusion coefficient of an ellipsoid with the semi-major A = 2a and semi-minor B = b, which is a theoretical value derived from the formulas in Ref. [19]. From Fig.…”

“…Particle diffusion in a narrow channel is a typical confined diffusion that has raised wide concern, [1,[16][17][18] such as porous flow, [16] microfluidic devices, [17] and transfer of species across biological membranes. [18] An isolated particle in a channel has been well studied; [19] however, the multiparticle case, which is more often encountered in practical applications, has not been sufficiently discussed due to the complexity of the interactions between particles, such as collision, coulomb interaction, magnetic interaction, and hydrodynamic interaction. In many multi-particle problems, particles have no charge or magnetism, and collisions between particles do not dominate the motion due to low linear density of particles in the channel.…”

Relationship between characteristic lengths and effective Saffman length in colloidal monolayers near a water–oil interface*

“…Confined colloidal systems are ubiquitous and important in many real scenarios. Examples of such systems include porous media, [1][2][3] microfluidic devices, [4][5][6][7][8][9][10][11] proteins in the cytoplasm, [2] and cell membranes. [12][13][14] The dynamics of a confined colloidal suspension depend on the boundary conditions of the system [15][16][17][18][19][20][21] and are more complicated than those of an unbounded free three-dimensional (3D) bulk liquid.…”