EAGER: Particle Concentration Measurements in Turbulent Flows using Magnetic Resonance Imaging

细小的固体颗粒，如沙子、尘埃或火山灰，在水或空气流动中的行为是广泛领域中的一个重要考虑因素。例如，环境粉尘会将喷气发动机的使用寿命缩短90%。最先进的实验只能在高度简化的系统中收集粒子数据。一种新的技术正在开发中，它使用传统的医学磁共振成像系统来定量测量粒子在复杂系统中的分布。产生的数据集将为工程师以及研究环境、生物和基础物理系统的研究人员带来广泛的好处。将进行一系列验证实验，以完成成像技术的开发，并确定其准确性和局限性。在开发出这项技术后，将进行另外两项实验，以证明新测量的广泛社会效益：一项是通过帮助设计更防尘的飞机发动机，另一项是通过阐明吸入的灰尘或喷雾液滴如何通过人体鼻子。在这个项目成功完成后，研究人员将有一个通用的方法来帮助他们了解任何粒子通过空气或水携带的系统。初步实验证明，磁共振成像可以用来定量和三维测量微粒的浓度。拟议的工作从一组详细的验证实验开始，以测试新实验方法在各种流动条件和颗粒浓度范围内的范围、分辨率和准确性。在验证实验之后，将使用两个与应用程序相关的测试用例作为测试平台，以继续开发该技术。第一部分将探索在飞机涡轮发动机冷却系统中经常使用的内部撞击冷却几何结构中颗粒的行为。在第二个测试案例中，将测量模型人类鼻腔内的颗粒浓度。除了开发这项技术外，这些测试案例还允许对两个具有重大研究兴趣的不同领域的粒子传输有新的理解。该项目的影响有可能远远超出本提案的范围，因为该技术可能被证明对计算模型验证、基本颗粒流研究或许多其他研究领域有用。

The behavior of small solid particles such as sand, dust or volcanic ash moving in water or air flows is an important consideration in a wide range of fields. For example, environmental dust can shorten a jet engine's service life by 90 percent. State-of-the-art experiments can only collect particle data in highly simplified systems. A new technique is being developed that uses conventional medical Magnetic Resonance Imaging systems to make quantitative measurements of how particles are distributed in complex systems. The data sets produced would have broad benefits for engineers, as well as for researchers studying environmental, biological, and fundamental physical systems. A series of validation experiments will be carried out to complete development of the imaging technique and to establish its accuracy and limitations. After the technique has been developed, two additional experiments will be performed to demonstrate broad societal benefits of the new measurements: one by assisting the design of more dust-resistant aircraft engines and the other by illuminating how inhaled dust or spray droplets move through the human nose. Following the successful completion of this project, researchers would have a general method to aid in their understanding of any system where particles are carried by air or water currents.Preliminary experiments have demonstrated that Magnetic Resonance Imaging can be used to measure the concentration of microparticles quantitatively and in three dimensions. The proposed work begins with a detailed set of validation experiments to test the range, resolution, and accuracy of the new experimental method across a range of flow conditions and particle concentrations. Following the validation experiments, two application-relevant test cases will be employed as test beds for continued development of the technique. The first will explore the behavior of particles in an internal impingement cooling geometry frequently employed in aircraft turbine engine cooling systems. In the second test case, particle concentration will be measured inside a model human nasal passage. In addition to developing the technique, the test cases allow for new understanding of particle transport in two disparate fields of significant research interest. The impact of the project has the potential to extend well past the scope of this proposal, as the technique could prove useful for computational model validation, fundamental particle-laden flow research, or a number of other research areas.