Numerical and experimental studies of heat transfer in steady and unsteady laminar or turbulent natural and mixed convective flows

稳定和非稳定层流或湍流自然对流和混合对流传热的数值和实验研究

• 批准号: 5573-2009
• 负责人: Oosthuizen, Patrick
• 金额: $ 1.53万
• 依托单位: Queen's University
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2012
• 资助国家: 加拿大
• 起止时间: 2012-01-01 至 2013-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=504967
• 关键词: Numerical; experimental; studies; heat; transfer

Research in five areas involving convective heat transfer will be undertaken. A number of electronic and electrical components are air-cooled using natural convection and involve geometric shapes that have not been dealt with in basic natural convective heat transfer studies. In the first part of the present work equations that can be used to predict the heat transfer rate in such situations will be developed. Both numerical and experimental studies will be undertaken. In the practical applications considered in the first area of research there is sometimes a low velocity flow over the components. The forced air velocity in such situations is often so low that the heat transfer is by mixed natural and forced convection. Such flows will be considered in the second area of research. Both numerical and experimental work will again be undertaken. The main aims of this work will be to define the conditions under which mixed convection exists. No systematic studies of numerical results obtained using a range of turbulence models for situations involving natural and mixed turbulent convective flows which are similar to air flows in buildings and for which experimental results exist have been undertaken. Such a study will be undertaken in the third study area, the main purpose being to derive recommendations as to which turbulence model to use in a particular flow situation. Most studies of heat transfer across window-blind systems assume that the natural convective flow over the room side of such systems is laminar. Turbulence and unsteady flow can, however, develop in such flows. Therefore in the fourth part of the research basic experimental and numerical studies of the development of turbulent and unsteady flow in window-blind systems will be undertaken. Gas flows in mini-channel systems in which the channel follows a wavy path will be considered in fifth part of the work. Such mini-channel systems are used in a number of practical situations and the flow in these systems can become unsteady at Reynolds numbers that are lower that that at which turbulent flow develops. The purpose of the study is to determine how the channel geometry affects the conditions under which unsteady flow develops.

将在涉及对流传热的五个领域进行研究。许多电子和电气组件使用自然对流进行气冷，并涉及在基本的自然对流传热研究中尚未处理的几何形状。在本工作方程的第一部分中，将开发用于预测这种情况下传热率的。将进行数值和实验研究。在研究的第一个领域中考虑的实际应用中，有时速度流量低于组件。在这种情况下的强制空气速度通常如此之低，以至于传热是通过混合自然和强制对流的。这些流程将在第二个研究领域考虑。数值和实验工作将再次进行。这项工作的主要目的是定义混合对流的条件。没有使用一系列湍流模型获得的数值结果的系统研究，这些模型涉及与建筑物中的空气流相似的自然和混合湍流流，并为此进行了实验结果。这项研究将在第三个研究领域进行，主要目的是提出有关在特定流动情况下要使用哪种湍流模型的建议。大多数跨窗户系统传热的研究都认为，这种系统室内的自然对流流是层流。但是，湍流和不稳定的流量可以在这种流程中发展。因此，将在研究的第四部分中进行窗户盲系统中湍流和不稳定流量发展的基本实验和数值研究。在小型通道系统中，通道遵循波浪路径的气流将在工作的第五部分中考虑。这种微型通道系统用于多种实际情况，这些系统中的流量可能会在雷诺数的数字中变得不稳定，而雷诺数的数量较低，而雷诺的数量较低。该研究的目的是确定通道几何形状如何影响不稳定流动的条件。