A study of boiling heat transfer mechanisms in micro-fluidic systems

由于今天的电子元件需要以更快的速度执行任务，因此已经生产了高功率集成电路以满足这种需求。这些高速电路预计会产生热通量，导致电路超过其允许温度。微通道热传递控制着微通道散热器的性能，这是一项旨在管理当今高端电子产品严格热要求的最新技术。微型散热器也有许多工业应用，包括微型冷却装置、高转换核反应堆、化学处理、微流体装置以及芯片上的微型动力装置。本研究的主要目的是探讨影响微散热器性能的热传递和流体流动现象。本研究的主要内容包括：1.建立基于实验的微通道内流动和传热的物理模型; 2.研究临界热流密度对热沉稳定运行的影响; 3.模拟沸腾传热和导致干化现象的机理; 4.建立微通道内流动和传热的数学模型。4-开发被动平面微混合器，以在完整的微流体系统中实现，例如微冷却系统或作为独立装置。拟议的研究应产生相当大的洞察力，先进的和创新的设计微热器件在公开文献中不可用。 拟议研究的结果将用于紧凑型电子产品的热管理，并将导致芯片上发电厂的发展，这将扩大便携式电子产品，机器人和小型车辆的市场。它还将导致产生新的基本知识，有关传热和流体流动的微系统，这将在公开文献中发表，并将有助于培训高素质的人才。

As today's electronic components are required to perform tasks at a faster rate, high-powered integrated circuits have been produced in order to meet this need. These high-speed circuits are expected to generate heat fluxes that will cause the circuit to exceed its allowable temperature. Microchannel heat transfer governs the performance of the microchannel heat sink, which is a recent technology aimed at managing the stringent thermal requirements of today's high-end electronics. Micro-heat sinks also have many industrial applications including micro-cooling devices, high conversion nuclear reactors, chemical processing, micro-fluidic devices, as well as micro-power-plants-on-chips. The principal objective of this research is to investigate the heat transfer and fluid flow phenomena affecting the performance of micro heat sinks. This proposal focuses particularly on: 1- developing physics-based models based on experiments for the flow and heat transfer phenomena in microchannels; 2- investigating the effect of critical heat flux on the stable operation of heat sinks; 3- modeling the mechanisms of boiling heat transfer and those leading to dry out phenomena; 4- developing passive planar micromixers, to be either implemented in a complete microfluidic system, such as a micro cooling system or as a stand-alone device. The proposed research should yield considerable insight into advanced and innovative designs of micro heat devices not available in the open literature. The outcome of the proposed research will be used in the thermal management of compact electronics, and will lead to the development of power-plants-on-chips, which will broaden the market of portable electronics, robotics, and small vehicles. It will also result in the generation of new basic knowledge regarding heat transfer and fluid flow related to microsystems, which will be published in the open literature, and will assist in training highly qualified personnel.