A Volumetric Particle Image Accelerometer for Fluid Dynamic Applications
Abstract
Turbulent flows invariably contain unsteady, three-dimensional features. Enhancing theunderstanding, performance and efficiency of fluid systems relies on a detailed understanding ofrelevant flow physics. The proposed Particle Image Accelerometry (PIA) system provides aquantum leap beyond Particle Image Velocimetry (PIV), which provides the velocity field of aflow by recording images of small particles immersed in the flow. Instead of providing the fluidvelocity, this system measures fluid acceleration. This is accomplished by first acquiring asequence of four instantaneous images of particles dispersed within a test volume in the flow. Inorder to reconstruct the volumetric distribution of the particles, each snapshot is imaged fromseveral different perspectives. This process provides four realizations of volumetric particledistributions separated by a small time step that are used to compute three independent velocityfields, which are then used to determine Lagrangian acceleration using state-of-the-art shake-theboxparticle tracking algorithms. The instantaneous illumination for each image is provided by alaser that produces four aligned, short-duration pulses. Furthermore, these measurements areacquired in a volumetric region of the flow – allowing fully three-dimensional, non-intrusivemeasurements. Because PIA measures the total derivative of flow velocity, it allows forunprecedented advances in analysis techniques via such as reduced-order modeling, dynamicmode decomposition, noise-source determination, and pressure field calculation. The complete“Particle Image Accelerometry” system will provide immediate benefits to current research andallow researchers to explore regimes that are currently beyond our reach.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Apr 09, 2018
- Source ID
- FA95501710404
Entities
People
- Louis N Cattafesta
Organizations
- Air Force Office of Scientific Research
- Florida State University
- United States Air Force