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Spray Cooling Heat Transfer Mechanisms

WV

West Virginia University

Development of a Monte Carlo model for spray cooling with boiling, based upon the fundamental physical mechanisms that occur in the process, but simplified so predictions are computed in a reasonable run time was attempted. Impingement of the huge number of droplets onto a heater surface, and subsequent detailed fluid, heat transfer, and phase change processes occurring in the liquid film forming on the heater was modeled via a combination of time scale analysis, experimental data, and Computational Fluid Dynamics results. Monte Carlo modeling of spray cooling is a unique and innovative approach that is far more efficient than first-principles attempts to simulate the fluid flow, heat transfer, and phase change processes that occur when individual spray droplets impinge onto a heater surface and interact with the liquid film, vapor bubbles, and one another. Within the project component, the experimental study of the dense spray impact and heat transfer, sufficient data has been obtained for use in the Monte Carlo model to account for the influence of the enhanced transient heat transfer in the individual droplet impact cavities. Video data for sprays gave impact cavity lifetimes that were significantly less than the cavity lifetimes measured for single droplet impacts under the single droplet impact studies. This gives us confidence in our time scale estimates for drop impact cavities to be re-covered due to subsequent nearby droplet impacts.

One frame of high-speed video image of surface Model prediction of heater surface for varying heater power levels:

John M. Kuhlman, Ph.D., Science PI, West Virginia University

www.nasa.gov/epscor/stimuli

Dr. Eric Silk, NASA Technical Monitor, GSFC

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NASA EPSCoR Stimuli 2014-15

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EPSCoR Stimuli 2014-15  

NASA Office of Education’s Aerospace Research & Career Development (ARCD) is pleased to release NASA EPSCoR Stimuli, a collection of univers...

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