Simultaneous Measurements of 3D Flow Structures and Wall Shear Stresses Using Digital Holographic Microscopy

提案编号：CTS-0625571主要研究者：约瑟夫·卡茨研究机构：约翰·霍普金斯大学学术成就：研究者们建议使用一种新的数字全息方法来研究典型湍流边界层中近壁的流动特征。这种实验技术是原始的，并承诺突破性的结果在湍流壁有界流动的理解。该小组对该建议印象深刻，并认为高分辨率数字全息显微镜（DHM）的发展将是一种有价值的湍流测量工具。该技术的高空间分辨率以及具有相对大的测量区域提供了获得速度、壁面剪切应力以及近壁流动结构的瞬时分布的能力。在不同时间记录的成对速度场中跟踪同一组粒子也提供了材料加速度。PI在过去一直非常富有成效和创新，使用该技术的初步结果令人信服。更广泛的影响：这项研究的成功完成将对湍流领域产生重大影响，因为它将推动一种新兴的、高空间分辨率的湍流测量工具，并提供关于典型边界层的宝贵数据集。这项工作将用于教育计划，涉及两名研究生以及高中学生从巴尔的摩理工学院。该技术的细节也将向社会公布。

PROPOSAL NO.: CTS-0625571PRINCIPAL INVESTIGATOR: JOSEPH KATZINSTITUTION: JOHNS HOPKINS UNIVERSITYIntellectual Merit: The investigators propose using a novel digital holographic method to examine flow features near the wall in canonical turbulent boundary layers. This experimental technique is original and promises groundbreaking results in the understanding of turbulent wall bounded flows. The panel was very impressed with the proposal and felt the development of the high resolution digital holographic microscopy (DHM) would be a valuable measurement tool for turbulence. The high spatial resolution of the technique as well has the relatively large measurement region provides the ability to obtain the instantaneous distribution of velocity, wall shear stress as well as near wall flow structures. Tracking the same group of particles in pairs of velocity fields recorded at different times also provides the material acceleration. The PIs have been extremely productive and innovative in the past and the preliminary results using the technique are convincing. Broader Impacts: Successful completion of this research would have a substantial impact in the field of turbulence by advancing an emerging, high spatial resolution measurement tool for turbulence, as well as providing a valuable data set on canonical boundary layers. This work will be used in an educational plan by involving two graduate students as well as senior high-school students from the Baltimore Polytechnic Institute. Details of the technique will also be made available to the community.