Advanced Molecular Tagging Velocimetry In Cryogenic Helium
Abstract
The objective of the proposed research is to develop advanced quantitative molecular tagging velocimetry (MTV) techniques applicable to cryogenic helium-4. Military vehicles and projectiles usually generate turbulent flows in air and ocean with extremely high Reynolds (Re) numbers. Understanding such flows is critical for optimizing the design of these vehicles and projectiles for better control and for improved energy efficiency. It has been known for decades that helium-4 has unique material properties that enable the generation of such highly turbulent flows in compact and economical equipment for laboratory research, which would not otherwise be possible with conventional fluids. However, the lack of reliable quantitative flow measurement tools applicable at cryogenic temperatures has hampered its applications. In recent years, the PIÕs group has made a breakthrough in developing a powerful quantitative MTV technique. This technique is based on the creation of He2 molecular tracer lines via femtosecond laser-field ionization in helium and imaging the resulted tracer lines via laser-induced fluorescence. In this proposal, a 1-year program aiming to advance this MTV technique for reliable velocity-field measurement is described. The major activity is to build and test a stereoscopic MTV setup for three-component velocity field measurement in helium. A grid formed by multiple tracer lines will be created first, and then the stereoscopic imaging system will be utilized to track the intersection points of the multi-line grid. These developments will lay a solid foundation for future high-fidelity quantitative studies of high Re turbulent flows in cryogenic helium, which will break new ground for model testing of various defense vehicles and projectiles that would be challenging to achieve otherwise.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Feb 14, 2019
- Source ID
- W911NF1910047
Entities
People
- Wei Guo
Organizations
- Army Contracting Command
- Florida State University
- United States Army