A 3D imaging system for turbulent dynamics
Abstract
Improving our understanding of how turbulence develops and decays, and finding ways to control its dynamics, is of both fundamental and significant practical interest. The turbulent state can take many forms; correspondingly, experimental platforms have been developed to take advantage of each manifestation to peer and gain insight into the turbulent state. We have developed a unique platform to address the the geometry and topology of turbulent flows: by colliding multiple vortex rings, we generate an isolated turbulent ÔblobÕ that is confined in the center of a tank (as supported by our current ARO single-PI grant). This technique for turbulent state engineering has the unique feature of building turbulence by combining controlled coherent vortices, thus enabling the controlled injection of helicity and energy. Here we propose a multi-camera pulsed-laser-illumination system that would enable us to measure the three-dimensional velocity fields within the turbulent blob and gain a time-resolved understanding of the turbulent dynamics of the blob as a whole. This will enable us to establish how a turbulent region immersed in an otherwise quiescent fluid spreads and decays and whether its growth, spreading, and decay can be controlled by tuning the knottedness of its vortex lines. The proposed system will further enable us to gain an understanding of how the injection of specific coherent vortex structures within turbulence alters pathways to energy dissipation. In addition this system will allow us to explore particle-turbulence interactions that can lead to de-mixing in turbulent flows, as well as the development of novel vorticity tracers that leverage multiple-wavelength multiple scattering information as indicators of particle orientation. The proposed apparatus will rely partially upon existing cameras in the Irvine lab, and will vastly streamline the technical aspects of turbulence measurements, making it appropriate for an advanced undergraduate to gain experience of turbulence measurements.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jul 09, 2020
- Source ID
- W911NF2010099
Entities
People
- William T. M. Irvine
Organizations
- Army Contracting Command
- United States Army
- University of Chicago