A New Facility for Experiments in Developing Wakes of Submerged Bodies
Abstract
A new facility for experiments in developing wakes of submerged bodies Abstract Much existing experimental and numerical work has been done to show that turbulent wakes developing in stably-stratified fluids have unusual properties, one of which is the generation and persistence of surprisingly regular and stable patterns of vorticity. These patterns have practical consequences in the possible detection of submerged vessels under realistic operating conditions. Despite the good agreement on the wake robustness and also in quantitative scaling laws, the conditions that are necessary and sufficient for the production of such a wake are not known. This is because, until now, neither numerical nor laboratory experiment has been able to calculate or measure the flow directly behind the body. This formidable problem has been solved experimentally in experiments (currently funded by ONR) that use refractive index matched fluids to allow accurate quantitative measurements, and we now have calibrated and debugged instrumentation that resolves three dimensional velocity components in very fine spatial and temporal resolution. The major drawback is that we are limited in Reynolds number, so length and/or velocity scales are not obviously scaled up to field conditions. Because the governing parameters involve both Reynolds and Froude number, the only way to make general experiments that scale reliably upwards in both parameters is to increase the length scales. Therefore we seek funds to build and instrument a tank which is significantly larger than the current one. It will allow experiments to be run over a range of Reynolds numbers so that scaling to field conditions will be predicted. The tank is part of an entirely new laboratory facility that has been built at USC, where undergraduate research projects will coexist with serious research. It will thus be a testbed and possibly recruiting tool for future Navy researchers.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2016
- Source ID
- N000141512915
Entities
People
- Robert Spedding
Organizations
- Office of Naval Research
- United States Navy
- University of Southern California