Micro/Macro (PIV/LIF) High Speed System for Heat Transfer Experiments
Abstract
Supercritical carbon dioxide (sCO2) is poised to revolutionize a range of Navys mission critical systems including portable power production unit, centralized coolant system, and standalone cooling device. However, lack of accurate predication tools (e.g., heat transfer coefficient correlations) and insufficient knowledge about the mechanisms controlling heat transfer processes are hindering its practical realization in key energy and cooling systems. Largediscrepancies and inconsistencies between available correlations which are mostly empirical and are based on adaptation of constant properties correlations, such as the Dittus-Boelter or Gnilienski correlations exacerbate the situation.A high-speed optical system to measure spatial sCO2 fluid temperature and velocity is requested. The system consists of two complementary modules a laser-Induced fluorescence (LIF) module for temperature measurements and particle image velocimetry (PIV) module for velocity measurements and will be available for a range of length scale measurements, from the micro scale to the convectional scale. The LIF, a spectroscopic technique, and the PIV, a nonintrusive laser optical measurement technique, are commonly used to study advanced convective heat transfer and fluid dynamics, respectively, and will be used extensively for a current Office of Naval Research (ONR) project and a plethora of future studies pertinent to the ONR. Timedependent velocity and temperature distribution of the flow will be elucidated. This in turn will allow to decouple the mechanisms controlling the heat transfer.The results from all these measurements with supplemental data/correlations from the literature will then be evaluated, consolidated, and broken down to separate heat transfer modes. They will then be reconstructed to develop transition criteria and mechanistic correlations that are independently validated. The measurements obtained through the requested equipment and theheat transfer and fluid flow processes that will be revealed will allow to better design and leverage supercritical carbon dioxide in a range of cooling and energy applications, such as cooling of high power electronic devices, heat exchangers for Rankine/Bryton power cycles, and refrigeration cycles.While the LIF/PIV system requested will considerably enhance the impact of the current project funded by the ONR, it has far broader use for a range of projects relevant to the DoD including diagnostics of microchannel liquid flows, two phase flow, and reacting flows. These processes are important for combustion processes, heat exchangers in power generation systems, cooling of high power systems, such as laser diode, CPUs, power amplifiers, etc.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- May 05, 2021
- Source ID
- N000142112358
Entities
People
- Subith Vasu Sumathi
Organizations
- Office of Naval Research
- United States Navy
- University of Central Florida Board of Trustees