MRI: Development of a Spatiotemporal Velocimetry with Simultaneous Size Measurements for Polydispersed Multi-Phase Flows

CTS-0521102P。Vlachos，弗吉尼亚理工学院这笔赠款是为了开发一种独特的仪器系统，用于空间分辨率、同时测量多分散多相流中的速度和颗粒尺寸，时间分辨率为kHz。该系统将用于生物流体力学、环境水力学和涡轮机械流动。这些看似互不相关的流体力学领域都需要解决尚未解答的问题，这些问题与流体运动以及多分散颗粒在各向异性流动中的运动有关，各向异性流动受湍流或不稳定的支配，涉及广泛的流动尺度和结构。现有仪器无法提供具有足够采样频率的时空分辨率测量，以捕捉湍流波动，同时测量颗粒大小和粒度分布。新的时间分辨数字粒子图像测速仪(TRDPIV)将带来硬件和算法的改进，以克服多分散多相流测量中存在的实验挑战。该新系统结合了传统DPIV在空间解析流动方面的优势，以及激光多普勒测速仪或热线测量高频速度波动的优势，以及相位多普勒粒子测速仪测量颗粒尺寸的优势。根据这笔赠款开发的仪器将对实验流体力学社区产生直接和广泛的影响。颗粒传输与碰撞、混凝、气浮、雾化和气泡动力学等多相流广泛存在于化工、航空航天、海军、发电、汽车和生物医药等行业。所有这些领域的研究人员和工程师都将获得一种新的独特的测量能力，从而对国家的工业和研究基础设施产生间接但非常广泛的影响。将通过重点突出的努力，在招聘人数不足的妇女和少数群体方面促进本科生和研究生研究，从而对多样性产生广泛和直接的影响。将通过对将开发和使用拟议系统的研究生和本科生进行彻底的培训和指导来实现教育效果。更广泛的教育影响将延伸到研究生和本科生的课堂，在那里，该系统将用于教授先进的实验方法，并在我们所需的流体力学课程中进行演示。

CTS-0521102P. Vlachos, Virginia Polytechnic InstituteThis grant is to develop a unique instrumentation system for spatially resolved, simultaneous velocity and particle size measurements in polydispersed multi-phase flows with kHz temporal resolution. The system will be used in biofluid mechanics, environmental hydraulics, and turbomachinery flows. These seemingly unrelated areas of fluid mechanics share the fundamental need to address unanswered questions relating the fluid motion along with the motion of polydispersed particulates in anisotropic flows that are governed by turbulence or unsteadiness encompassing a wide range of flow scales and structures. Existing instrumentation fails to deliver spatio-temporally resolved measurements with sufficient sampling frequency to capture turbulent fluctuations while simultaneously measuring the particulate size and size distribution. The new Time Resolved Digital Particle Image Velocimeter (TRDPIV) instrumentation will deliver hardware and algorithm advancements to overcome the experimental challenges present in polydispersed multiphase flow measurements. The new system combines the advantages of conventional DPIV to spatially resolve a flow with the advantages of Laser Doppler Velocimetry or hot-wires to measure high frequency velocity fluctuations and the advantages of Phase Doppler Particle Anemometry to measure particle sizes. The instrumentation developed under this grant will have a direct and broad impact upon the experimental fluid mechanics community. Multi-phase flows such as particle transport and collision, coagulation, flotation, spray atomization and bubble dynamics are present in a wide variety of industries such as chemical, aeronautical/aerospace, naval, power generation, automotive and biomedical. A new unique measurement capability will be available to researchers and engineers in all these areas thus having an indirect yet very broad impact on the nation's industrial, and research infrastructure. Broad and direct impact on diversity will be achieved through well-focused efforts to promote undergraduate and graduate research in recruiting underrepresented women and minorities. Educational impact will be achieved through thorough training and mentoring of graduate and undergraduate students that will be developing and using the proposed system. The broader educational impacts will extend to the graduate and undergraduate classrooms where the system will be used for teaching advanced experimental methods and performing demonstrations in our required fluid mechanics courses.