Effects of Surface Wettability and Roughness on the Heat Transfer Performance of Fluid Flowing through Microchannels

Abstract

Abstract:The surface characteristics, such as wettability and roughness, play an important role in heat transfer performance in the field of microfluidic flow. In this paper, the process of a hot liquid flowing through a microchannel with cold walls, which possesses different surface wettabilities and microstructures, is simulated by a transient double-distribution function (DDF) two-phase thermal lattice Boltzmann BGK (LBGK) model. The Shan-Chen multiphase LBGK model is used to describe the flow field and the independent distribution function is introduced to solve the temperature field. The simulation results show that the roughness of the channel wall improves the heat transfer, no matter what the surface wettability is. These simulations reveal that the heat exchange characteristics are directly related to the flow behavior. For the smooth-superhydrophobic-surface flow, a gas film forms that acts as an insulating layer since the thermal conductivity of the gas is relatively small in comparison to that of a liquid. In case of the rough-superhydrophobic-surface flow, the vortex motion of the gas within the grooves significantly enhances the heat exchange between the fluid and wall.

Investigation of Superhydrophobic/Hydrophobic Materials Properties Using Electrospinning Technique

“…The high amount of roughness is unwanted and would be expensive to produce. This also gives undesirable properties for the manufacturing of hydrophobic coating, which in general have very smooth surface characteristics (5). This research focused on the fabrication of superhydrophobic/hydrophobic nanocomposites coating by electrospinning technique and aimed to study the surface morphology of coated surface.…”

Weathering Effect on Surface Characteristics of Superhydrophobic/ Hydrophobic Nanocomposites Coating

“…Surface roughness define the changes alteration on coated substrate and how react to the ambient environment, higher roughness value is undesirable, hard and expensively to control the product. Also granted unwanted properties for the fabrication of hydrophobic coating which generally known that owns very smooth surface properties [4]. Hardness is the resist of surface deformation produced by indentation and shows how surface can interact to the environmental situation and defect that can stick and arise with its properties.…”

Influence of Stem-cell Size and Culture Media Flowing Modality on Cell’s Fate within a Microchannel; a Numerical Analysis

“…Many studies showed that conventional fluid dynamics theories are generally applicable in microchannels fluid flow analysis [8,9]. However, due to the small size of the microchannel, parameters such as surface roughness and wettability of their walls can cause differences in the way fluid flows in larger-scale channels [10][11][12]. Another factor that can add to studying fluid flow in microchannels, especially in biological systems, is the inherent complexity of biological fluids.…”