MRI: Acquisition of an Integrated High Frame-Rate Particle Image Velocimetry (HFR-PIV) System

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CBET-0821608WosnikThis MRI project funds for the acquisition of an integrated High Frame-Rate Particle Image Velocimetry (HFR-PIV) system, to obtain highresolution, time-resolved, whole-field, quantitative experimental data in a variety of turbulent flows. Time-resolved whole-field flow measurements - inaccessible prior to the development of HFR-PIV systems - have the potential to greatly advance our understanding of flow physics, and will play an important role in the creation of advanced simulation tools, for example the parametrization of subgrid-scale processes for large eddy simulations. HFR-PIV will also be a key measurement technique to be used in the NSF EPSCoR-funded large scale facility for the development and testing of sensing, prediction, actuation and control technologies in high Reynolds number turbulent boundary layer flows (Klewicki et al. 2006). The instrumentation will be used by the principle investigators and their research groups, other UNH researchers working in experimental fluid dynamics, as well as students in new graduate experimental courses. Intellectual Merit: The instrument allows spatial structure to be understood in the context of its temporal evolution. This capability is a primary obstacle preventing our understanding of complex fluid phenomena. For example, high frame-rate PIV of both the liquid and gas phases in cavitating flows will, for the first time, provide a bridge between the large body of qualitative work (high speed photography, videos) and quantitative flow measurement. In turbulent boundary layers, advancing the current state of knowledge of the transport mechanisms requires flow field information that captures the interactions across spatial scales of the dynamical motions as these motions evolve in time. More broadly, a description of these scale interactions is precisely the information required in the development of viable subgrid models in LES computations. The HFR-PIV system uniquely provides this capability. Current research activities that will benefit directly from the HFR-PIV system are:- Investigation of cavitation dynamics on hydrofoils and turbine blades, a first step towards control of partially cavitating flows- Scale separation effects on the dynamical mechanisms of turbulent boundary layers- Experimental Studies of Separated Flows with Polymer Ejection for Control of Turbulence Generated Noise- Development and Testing of Viable Ocean Turbine Designs for In-Stream Tidal EnergyBroader Impact: The thesis research and research education of approximately 8 Ph.D, 12 M.S. and a number of undergraduate students will be directly affected by the availability of this instrument through the three years of this grant. The instrument will be used in newly created experimental graduate courses. Additionally, the time-resolved quantitative flow visualization movies that come naturally from research activities will be used in undergraduate fluid mechanics education. Having an experimental tool that can inspire students to explore the complexity of fluid phenomena will make it easier to attract students of all backgrounds to this subject. Many broader societal impacts may also result from the integration of the HFR-PIV system into the described activities. For example, the outcomes from the research on high Reynolds number boundary layers, which are omnipresent in many natural processes and technologically important flows. Similarly, this instrument will substantively increase our capacity to explore fluid dynamical phenomena important to the development of alternative energy related technologies. This capability directly supports broader, College-wide, initiatives.