- Author
- Tinker, S. C. | diMarzo, M.
- Title
- Water Droplet Evaporation from Radiantly Heated Solids. Final Report. September 1992-May 1994.
- Coporate
- Maryland Univ., College Park
- Sponsor
- National Institute of Standards and Technology, Gaithersburg, MD
- Report
- NIST GCR 95-665, December 1994, 158 p.
- Distribution
- Available from National Technical Information Service
- Contract
- NIST-GRANT-70NANB1H1173
- Keywords
- industrial plants | cooling | drop sizes | droplets | evaporation | fire research | solid surfaces | sprinkler systems | water sprays
- Abstract
- [Former title: Fire Protection in Large Industrial Fires] A model describing the configuration of a water droplet evaporating on the surface of a radiantly heated semi-infinite solid is developed. A shape factor and the solid-liquid-vapor contact angle describe the transient droplet shape, though the initial value of the latter parameter is found to have a negligible effect on the droplet's evaporation. The droplet shape model and a modified radiation heat term are incorporated into a previously developed computer model to predict the evaporation of a single droplet on a semi-infinite solid subjected to radiant heat input. The code predicts transient temperature profiles that agree well with experiment. A simplified, closed-form solution for the prediction of surface temperatures in the vicinity of an evaporating droplet is used to fit the data produced by the single droplet model. This closed-form solution facilitates calculations used in a model for the cooling of a surface by the evaporation of a sparse spray of water. The previously collected data base for sparse spray cooling using degassed water is expanded with a new set of experiments using water containing dissolved gases.