Fundamental Experimental and Numerical Convective Heat Transfer Research

建议的研究计划的主要重点是改进对单相对流换热的基本理解。复杂对流换热过程的知识对于熟练设计涉及流体换热的各种技术至关重要。工程应用覆盖了经济的所有部门。 在过去的探索资助期间，申请者开发了一种新的分析和数值方法(称为dQdT)，该方法可以更有效地描述具有多个驱动温差的多个表面之间进行热交换的情况下的对流换热。这项研究的目标之一是将这一新方法推广为表征多温度对流的一种实验方法。这将为调查增加一种新的研究方法，并将使dQdT能够验证数字预测。此外，将应用dQdT的数值实现来提高我们对建筑物中遇到的高度复杂的流动的基本物理的理解。其目的是为了提高建筑能耗分析中热传递预测的准确性。预测建筑物热性能的能力的提高将导致更舒适和节能的设计。 这项拟议研究的另一个分支研究了使用稀纳米流体可以实现的对流换热增强。纳米流体将纳米颗粒和基础流体结合在一起，创造出具有广泛冷却技术潜力的工作液。目前，对流换热强化的大小和机理尚不清楚。这项拟议的研究将使用一种名为激光干涉测量的光学测量技术来研究透明水基纳米流体的这种影响。光学方法量化和可视化整个流体温度场的能力为深入了解稀薄纳米流体产生的热传递强化提供了重要的机会。 拟议的研究将作为一个综合计划进行，涉及最先进的实验方法和计算流体动力学建模之间的平衡。这项研究将为博士、硕士和本科生提供优秀的培训经验，并将促进对流换热领域的根本性进展。

The primary focus of the proposed research program is the improved fundamental understanding of single phase convective heat transfer. Knowledge of complex convective heat transfer processes is essential for the skillful design of a wide range of technologies that involve the exchange of heat by a fluid. The engineering applications span all sectors of the economy. In the past Discovery Grant period, the applicant developed a new analytical and numerical approach (called dQdT) that more effectively characterizes convective heat transfer in situations where heat is exchanged between multiple surfaces with multiple driving temperature differences. One goal of the proposed research is to extend this new approach as an experimental method for characterizing multi-temperature convection. This will add a new research technique for investigations, and will enable the validation of numerical predictions by dQdT. Also, the numerical implementation of dQdT will be applied to improve our understanding of the underlying physics of the highly complex flows that are encountered in buildings. The motivation is to refine the accuracy of heat transfer predictions in building energy analysis. Improvements in the capability to predict the thermal performance of buildings will lead to more comfortable and energy efficient designs. Another arm of the proposed research examines the convective heat transfer enhancements that can be achieved using dilute nanofluids. Nanofluids combine nanoparticles and base fluids to create working fluids that have the potential for use in a wide range of cooling technologies. At present, the magnitude and mechanisms of the convective heat transfer enhancement remain poorly understood. The proposed research will investigate this effect for transparent water-based nanofluids, using an optical measurement technique called laser interferometry. The ability of optical methods to quantify and visualize the entire fluid temperature field opens up important opportunities for new fundamental insights into the heat transfer enhancements produced by dilute nanofluids. The proposed research will be undertaken as an integrated program involving a balance between state-of-the-art experimental methods and computational fluid dynamics modeling. This research will provide excellent training experiences for doctoral, master's and undergraduate students, and will lead to fundamental advances in the field of convective heat transfer.