Toward Quantitative Three-Dimensional and Three-Component Velocimetry in Reactive Flows

被称为3D3C速度的基本属性在广泛的学科中都很重要，它的分辨率对于许多社会挑战都很重要，包括清洁能源。例如，为了更好地理解和更好地设计能源系统，包括燃气轮机、风力涡轮机和氢发动机，需要3D3C速度。3D3C速度是三个维度（3D）的流速，三个分量（3C）都被分解。测量这一特性是非常重要的，人们已经投入了大量的精力来发明能够获得3D3C速度测量的测速技术。然而，这些测量仍然存在挑战，特别是在可量化的准确性和反应流方面。该项目旨在实现反应流中3D3C速度的定量测量，为设计更清洁的能源解决方案铺平道路。此外，该项目将整合到研究人员的日常教学活动、K-12外展活动、设计项目和工业合作中。在科学上，该项目将集中在一个问题上：我们目前在反应流中使用的3D3C测速技术的不确定性。本项目拟解决这一问题，分3步逐步实现3D3C速度的定量测量。第一步的目标是在基本层面上理解现有技术的不确定性。这一步将设计新颖的实验，以便可以先验地知道地面真值速度，并可以直接量化误差。在第一步的基础上，第二步的目标是发明新的策略，以显著提高3D3C测速精度。初步结果确定了几个有前途的想法，包括新的层析重建算法和湍流引起的波束转向的主动校正。最后，第三步提出将第一步和第二步的新理解和新策略应用于现有数据的解释，为社区建立一个精度更高、误差条定义明确的新数据库。速度是最基本的属性，既是模型比较的关键输入，也是关键输出。本项目所寻求的定量3D3C结果有望成为研究界有价值的数据库，既可以验证现有模型，也可以激发新的见解和新模型。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

The fundamental property called 3D3C velocity is important in a wide range of disciplines and its resolution is important for many societal challenges, including clean energy. For example, 3D3C velocity is required for better understanding and better design of energy systems, including gas turbines, wind turbines, and hydrogen engines. 3D3C velocity is flow velocity in all three dimensions (3D) with all three components (3C) resolved. Measuring this property is very important and considerable efforts have been invested to invent velocimetry techniques that can obtain 3D3C velocity measurements. However, challenges remain in these measurements, especially around quantifiable accuracy and in reactive flows. This project aims to enable quantitative 3D3C velocity measurements in reactive flows to pave the way for the design of cleaner energy solutions. In addition, the project will be integrated into the researchers’ daily teaching activities, K-12 outreach activities, design projects, and industrial collaborations.Scientifically, the project will concentrate on one issue: the poorly-understood uncertainties of our current 3D3C velocimetry techniques in reactive flows. This project proposes to resolve this issue and enable quantitative 3D3C velocity measurements in 3 progressive steps. Step I aims at understanding existing techniques’ uncertainties at a fundamental level. This step will design novel experiments so that the ground truth velocity can be known a priori and the errors can be directly quantified. Based on Step I, Step II then aims at inventing new strategies to significantly improve the accuracy of 3D3C velocimetry. Preliminary results have identified several promising ideas including new tomographic reconstruction algorithms and active correction of beam-steering caused by turbulence. And finally, Step III proposes to apply the new understanding from Steps I and II and new strategies to interpret existing data to establish a new database with enhanced accuracy and well-defined error bars for the community. Velocity is the most basic property both as a key input and a key output for model comparison. The quantitative 3D3C results sought in this project are expected to be a valuable database for the research community, both to validate existing models and also to inspire new insights and new models.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.