A Surface Texture Design to Obstruct the Liquid Migration Induced by Omnidirectional Thermal Gradients
Qingwen Dai1, Wei Huang1, Xiaolei Wang1,2
1College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics & Astronautics , Nanjing 210016, China.
Langmuir : the ACS Journal of Surfaces and Colloids
|September 4, 2015
Summary
Microdimples on surfaces effectively prevent liquid lubricant migration driven by thermal gradients. These surface patterns obstruct and retain liquids, crucial for maintaining lubrication on rubbing surfaces.
Area of Science:
- Surface science and tribology
- Fluid dynamics and microfluidics
Background:
- Thermo-capillary migration, driven by surface thermal gradients, causes unwanted liquid flow.
- Preventing lubricant migration on rubbing surfaces is critical for reducing friction and wear.
Purpose of the Study:
- To investigate the use of microdimple patterns to obstruct thermo-capillary migration.
- To analyze the effect of microdimple geometry on liquid migration behavior.
Main Methods:
- Fabrication of microdimple patterns on SUS316 stainless steel surfaces.
- Experimental investigation of paraffin oil migration on these patterned surfaces.
- Focus on interfacial flow dynamics around microdimples.
Main Results:
- Microdimple patterns significantly obstruct thermo-capillary migration.
- Individual dimples exhibit a liquid-retaining effect.
- Interactions between adjacent dimples influence migration patterns.
Conclusions:
- Microdimple surface texturing is an effective strategy to control liquid migration.
- Surface topography can be engineered to manage fluid behavior in thermal gradients.
- Findings are relevant for lubricant retention in tribological systems.
Related Concept Videos
01:22Surface Tension of Fluid
2.0K
Surface tension is a fundamental property of fluids, occurring at the boundary between a liquid and a gas or between two immiscible liquids. This phenomenon arises from the cohesive forces between molecules at the fluid's surface, creating an effect similar to a stretched elastic membrane. Inside each fluid, molecules are equally attracted in all directions by neighboring molecules, but surface molecules experience a net inward force, resulting in surface tension.
Surface tension varies...
Surface tension varies...
2.0K
01:02Fluid Pressure over Flat Plate of Variable Width
2.2K
When a flat plate is submerged in a fluid, the fluid exerts pressure on the plate. This pressure can lead to many different phenomena, including drag and buoyancy. To understand the behavior of the fluid over a flat plate of variable width, it is essential to analyze the distribution of the pressure exerted.
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
The pressure distribution on the plate can be calculated by determining the force that acts on a differential area strip of the plate. Thus, the magnitude of the force is equal to the...
2.2K
01:12Fluid Pressure over Curved Plate of Constant Width
2.0K
When a curved plate of constant width is submerged in a liquid, the pressure acting normal to the plate varies continuously both in magnitude and direction. Calculating the magnitude and location of the resultant force at a point is often challenging for such cases. One of the methods to determine the resultant force and its location involves separately calculating the horizontal and vertical components of the resultant force. This complex calculation can be simplified by representing the...
2.0K
01:18Boundary Layer Characteristics
851
When a fluid encounters a solid surface, a boundary layer forms due to the interaction between the fluid's motion and the stationary surface. This phenomenon is characterized by a thin region adjacent to the surface where viscous forces dominate, influencing the fluid's velocity profile. The development of the boundary layer begins at the leading edge of the surface and evolves as the fluid moves downstream.As the fluid flows over the surface, friction between the fluid and the wall slows down...
851
01:05Fluid Pressure over Flat Plate of Constant Width
2.6K
When a body is submerged in water, it experiences fluid pressure acting normal on its surface and distributed over its area. For better design structures, it is crucial to determine the magnitude and location of the resultant force acting on the surface. In the case of a rectangular plate of constant width submerged in water, the pressure increases with depth, resulting in a linearly varying trapezoidal pressure distribution from the upper to the lower edge of the plate.
The resultant force...
The resultant force...
2.6K
01:27Thermal expansion and Thermal stress: Problem Solving
2.4K
San Francisco's Golden Gate Bridge is exposed to temperatures ranging from -15 °C to 40 °C. At its coldest, the main span of the bridge is 1275 m long. Assuming that the bridge is made entirely of steel, what is the change in its length between these temperatures?
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55...
To solve the problem, first, identify the known and unknown quantities. The initial length (L) of the bridge is 1275 m, the coefficient of linear expansion (α) for steel is 12 x 10-6/°C, and the change in temperature (ΔT) is 55...
2.4K