Direct Measurements of Dissipation Rate and Determination of the Velocity/pressure-gradient Correlation in Complex High Reynolds Number Turbulent Flows

提案编号： CTS-0233653提案类型：发起人主要发起人：Roger L.辛普森研究所：弗吉尼亚州波利尼西亚大学，直接测量耗散率和复杂湍流的相关性有一个明确的需要，大大改善湍流模型的实际三维高雷诺数湍流，以促进发展强大的和准确的计算工具。 改进将对所有流体机械的设计计算产生巨大影响，包括飞机、潜艇、喷气发动机等以及大气和海洋流动的预测。在许多模型中使用的支配性的哈罗德平均方程中的一些项从未被直接测量过，并且基本的理论思想是高度不确定的。一种新设计的激光多普勒测速仪正在使用和进一步开发，可以立即确定的位置，速度和加速度的三个组成部分的多个粒子，遵循200微米的测量体积内的流动。不仅将颗粒的瞬时位置确定到1微米（0.00004英寸）的不确定性，但瞬时变形率和角速度的流动将获得，导致确定的瞬时值的重要条款的基本方程。 这些信息对于改进湍流建模是重要的。实验技术将用于获得三种基本构件流的数据：二维平板零平均压力梯度边界层（动量厚度雷诺数在7，000至23，000范围内），具有孤立粗糙度的二维湍流边界层和三维粗糙壁边界层。 从这项拟议的研究的实验结果将是第一个可用的数据集与完整的测量的所有湍流量在相对较高的雷诺数的雷诺平均模型方程。这项研究将产生广泛的影响。计划与湍流建模者进行重要的互动和合作，这将广泛传播结果，以加强科学和技术理解。其他广泛的影响是美国本科生和研究生在使用这种尖端的研究技术，重大贡献的研究基础设施，通过开发一种新的仪器，并通过湍流建模的实际应用中的进步，为社会带来好处的教育。

PROPOSAL NO.: CTS-0233653PROPOSAL TYPE: INVESTIGATOR INITIATEDPRINCIPAL INVESTIGATORS: ROGER L. SIMPSONINSTITUTION: VIRGINIA POLYTECHNIC INST. DIRECT MEASUREMENTS OF DISSIPATION RATE AND CORRELATIONS IN COMPLEX TURBULENT FLOWSThere is a clear need to greatly improve turbulent flow models for practical three-dimensional high Reynolds number turbulent flows in order to facilitate development of robust and accurate computational tools. Improvements will have a great impact on the design calculations of all fluid machinery, including aircraft, submarines, jet engines, etc. as well as the prediction of atmospheric and ocean flows. Some terms in the governing Reynolds-averaged equations used in many models have never been directly measured and the underlying theoretical ideas are highly uncertain.This program will provide a major experimental breakthrough. A newly designed type of laser-Doppler velocimeter is being used and further developed that can determine instantaneously the three components of position, velocity, and acceleration of multiple particles that follow the flow within a 200 micron measurement volume. Not only will the instantaneous position of the particles be determined to within 1 micron (0.00004 inches) uncertainty, but the instantaneous rate-of-deformation and angular velocity of the flow will be obtained, leading to the determination of the instantaneous values of important terms in the fundamental equations. The information is important for improved turbulence modeling. The experimental technique will be used to obtain data for three fundamental building block flows: 2-D flat plate zero mean pressure gradient boundary layers (momentum thickness Reynolds number in the range 7,000 to 23,000), two-dimensional turbulent boundary layers with isolated roughness, and three-dimensional rough-wall boundary layers. The experimental results from this proposed research will be the first available data sets with complete measurements of all turbulent quantities in the Reynolds-averaged modeling equations at relatively high Reynolds numbers. This research will have a number of broad impacts. Significant interaction and collaboration with turbulence modelers is planned, which will broadly disseminate the results for enhanced scientific and technical understanding. Other broad impacts are the education of US undergraduate and graduate students in the use of this cutting-edge research technique, significant contributions to research infrastructure by developing a new instrument, and benefits to society through advancements in turbulence modeling for practical applications.