Oscillation and Heat Transfer of Hybrid Fluid on the Micro/Nanostructured Surface
Abstract
Short Work Statement:Task 1 ~ Demonstrate a micro/nanostructured surface: The innovative micro/nanostructured surface will be demonstrated which can give liquid metal and low-latent-heat fluid (LLHF) different wetting characteristics, i.e., liquid metal on the micro/nanostructured surface is hydrophobic, the LLHF on the micro/nanostructured surface is hydrophilic.Task 2 ~ Develop mathematical models: A mathematical model of thin film evaporation of LLHF liquid film formed on the inner surface of cavities will first be developed with a focus on the curvature effect on fluid flow and evaporation of thin film. A mathematical model of film condensation on the liquid metal surface will be developed to better understand how LLHF film condensation enhances heat transfer of liquid metal in the evaporating section. A commercial software will be used to study the vortex effect on heat transfer to optimize the micro/nanostructures. With this new information, a mechanical vibration model for whole OHP systems will be developed to better understand fluid flow and heat transfer of oscillating hybrid fluids (liquid metal and LLHF).Task 3 ~ Demonstrate how wetting characteristics can enhance heat transfer: For the hybrid fluid OHPs, where hybrid fluids experience oscillating motions and rapid phase change (particularly in thin film regions), the experimental investigation aims at the wetting characteristics effect on oscillating motion and heat transfer enhancement of a train of liquid plugs and vapor bubbles of hybrid fluids through visual observation and thermal measurement. Based on the new information to be obtained, a highly efficient OHP charged with hybrid fluids will be demonstrated for effective cooling of extra-high heat flux applications up to 1000 W/cm2.Abstract:The goal of the proposed research is to develop a fundamental understanding of the oscillating flow and heat transfer of a train of liquid plugs and vapor bubbles of hybrid fluids (liquid metal with a higher thermal conductivity and a fluid with a low latent heat) in an OHP with micro/nanostructured inner surfaces. The focus is to understand the mechanisms of integrated heat transfer enhancement of oscillating motion enhanced by the thin film evolution and evaporation of low-latent-heat fluid, vortex formation of vapor and liquid, condensation on a liquid-metal surface, flow resistance reduction, and high thermal conductivity of room-temperature liquid metal. Micro/nanostructure fabrication, theoretical studies, and numerical simulations, as well as an experimental investigation will be integrated to identify the wetting characteristics~ effects on oscillating motion, oscillating heat transfer, thin film evaporation, condensation, and pressure dropreduction of hybrid fluids (liquid metal and water) in an OHP and to resolve fundamental issues in the heat transfer enhancement of the proposed hybrid OHP. An innovative nano/microstructured surface will be demonstrated, which gives liquid metal and water different wetting characteristics. When water flows through the micro/nanostructured surface, it is hydrophilic. The hydrophilicwetting characteristics can enhance thin film evaporation which significantly increases the driving force for the oscillating motion. When liquid metal flows through the micro/nanostructured surface, it is hydrophobic. Hydrophobic wetting characteristics of liquid metal can significantly enhance convection heat transfer of oscillating flow from the evaporator to the condenser through the high thermal conductivity of liquid metal, flow resistance reduction, and condensation heat transfer. Mathematical models of thin film evaporation, condensation heat transfer, vortex in cavities, and mechanical vibration are integrated together with the experimental investigation to better understand fluid flow and heat transfer of a train of liquid plugs and vapor bubbles of oscillating hybrid fluids in an OHP. Based on the fundamental understanding thus develop
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Nov 09, 2018
- Source ID
- N000141912006
Entities
People
- Hongbin Ma
Organizations
- Office of Naval Research
- United States Navy
- University of Missouri System