对粘性弹性纳米流体作为沉浸式冷却应用的传热液体进行原子学研究
Bharath Ravikumar1, Ioannis K Karathanassis1, Timothy Smith2
1School of Science and Technology, City, University of London, EC1 V 0HB London, U.K.
概括
带有石墨烯或碳纳米管的粘性弹性纳米流体显示出增强的热容量,而铜纳米流体改善了热传导. 这些量身定制的纳米流体为浸泡冷却提供了超过80%的传热增强.
科学领域:
- 材料科学 材料科学 材料科学
- 纳米技术纳米技术
- 热力学是一种热力学.
背景情况:
- 浸泡冷却需要先进的传热流体.
- 纳米流体提供了增强热性能的潜力.
- 粘弹性可以影响流体动力学和热传递.
研究的目的:
- 为了比较评估粘性弹性纳米流体的热性能和传热系数.
- 研究纳米粒子化学和形状对性能的影响.
- 为了评估其适用于浸泡冷却应用的适用性.
主要方法:
- 使用了分子动力学模拟.
- 铜纳米球,石墨烯和碳纳米管 (CNT) 在PAO-2中分散,度为2.6%.
- 使用OCP聚合物链诱导粘性弹性.
主要成果:
- 碳基纳米粒子 (石墨烯,CNT) 增加了特定热容量.
- 基于铜的纳米流体显示特定热容量下降,但由于声DOS匹配,增强了传热.
- 石墨烯和CNT补偿了较低的DOS匹配与高的内在导热率.
- 粘性弹性纳米流体显示,由于链扩张,Couette流中的传热系数提高了80%以上.
结论:
- 纳米颗粒的选择显著影响热性质和热传递.
- 粘性弹性,特别是来自聚合物链扩张的粘性,大大提高了传热系数.
- 这些工程纳米流体对高效的沉浸式冷却系统有希望.
更多相关视频
11:38Combining Microfluidics and Microrheology to Determine Rheological Properties of Soft Matter during Repeated Phase Transitions
Published on: April 19, 2018
7.9K
14:24Manufacturing of Three-dimensionally Microstructured Nanocomposites through Microfluidic Infiltration
Published on: March 12, 2014
12.3K
相关概念视频
Viscosity of Fluid
342
Viscosity measures the resistance a fluid offers to flow and deformation. It results from internal friction between layers of fluid moving relative to one another. Dynamic viscosity, denoted by the Greek letter mu (μ), quantifies the force needed to move one fluid layer over another. For Newtonian fluids like water and air, the relationship between the shearing stress and the rate of shearing strain is linear, meaning their viscosity remains constant regardless of the applied stress.
342
Mechanisms of Heat Transfer II
3.2K
In convection, thermal energy is carried by the large-scale flow of matter. Ocean currents and large-scale atmospheric circulation, which result from the buoyancy of warm air and water, transfer hot air from the tropics toward the poles and cold air from the poles toward the tropics. The Earth’s rotation interacts with those flows, causing the observed eastward flow of air in the temperate zones. Convection dominates heat transfer by air, and the amount of available space for the airflow...
3.2K
Surface Tension, Capillary Action, and Viscosity
27.5K
Surface Tension
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
The various IMFs between identical molecules of a substance are examples of cohesive forces. The molecules within a liquid are surrounded by other molecules and are attracted equally in all directions by the cohesive forces within the liquid. However, the molecules on the surface of a liquid are attracted only by about one-half as many molecules. Because of the unbalanced molecular attractions on the surface molecules, liquids contract to form a shape that minimizes the number...
27.5K
Mechanisms of Heat Transfer
262
Heat transfer between the human body and its environment occurs through four main mechanisms: conduction, convection, radiation, and evaporation.
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
Conduction, accounting for approximately 3% of body heat loss at rest, is the process of exchanging heat between molecules of two materials in direct contact. This can result in both heat loss and gain. For instance, when the body is submerged in water, which conducts heat 20 times more effectively than air, it can either lose or gain significant...
262
Mechanisms of Heat Transfer I
4.2K
Just as interesting as the effects of heat transfer on a system are the methods by which the heat transfer occur. Whenever there is a temperature difference, heat transfer occurs. It may occur rapidly, such as through a cooking pan, or slowly, such as through the walls of a picnic ice box. So many processes involve heat transfer that it is hard to imagine a situation where no heat transfer occurs. Yet, every heat transfer takes place by only three methods: conduction, convection, and radiation.
4.2K
Characteristics of Fluids
3.8K
When a force is applied parallel to the top surface of a solid, it resists the applied force due to the internal frictional forces between the layers of the solid known as shearing resistance. However, when the force is removed, the shearing forces restore the original shape of the solid. Other deformation forces also cause temporary changes in shape if the forces are not beyond a threshold magnitude. Solids tend to retain their shape, making the study of their rest and motion easier. Beyond...
3.8K
