Accession Number : ADA263495


Title :   Pulse Mitigation and Heat Transfer Enhancement Techniques. Volume 1. Spray Cooling.


Descriptive Note : Final rept. 1 Jul 87-31 Jul 92,


Corporate Author : KENTUCKY UNIV LEXINGTON DEPT OF MECHANICAL ENGINEERING


Personal Author(s) : Chow, L C ; Tilton, D E ; Pais, M R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a263495.pdf


Report Date : Aug 1992


Pagination or Media Count : 95


Abstract : This report presents an experimental and theoretical investigation of spray cooling. A complete study is presented for surfaces maintained between the fluid saturation temperature and the Leidenfrost temperature. Experiments were conducted to analyze the effects of spray and surface conditions on the heat transfer. Different mechanisms causing the critical heat flux (CHF) are identified. For dropwise evaporation, CHF results when the surface heat flux exceeds the latent heat content of the spray. As the flow rate is increased, droplet conglomeration and surface flooding result. For low flow rate cases with a flooded surface, CHF is caused by a liquid deficiency resulting from droplet expulsion caused by the nucleating bubbles within the liquid film. For higher flow rate cases, CHF occurs when the vapor generation rate on the surface is so high that a vapor barrier is formed.


Descriptors :   *HEAT TRANSFER , *COOLING , *SPRAYS , TEMPERATURE , LIQUIDS , VAPORS , FLOW RATE , SURFACE PROPERTIES , DEFICIENCIES , DROPS , IMPINGEMENT , EXPULSION , FLOODING , HEAT FLUX , EVAPORATION , TRANSFER , FLUIDS , BARRIERS , BUBBLES , PULSES , LATENT HEAT , SATURATION , FILMS , RATES , NUCLEATION


Subject Categories : Physical Chemistry
      Air Condition, Heating, Lighting & Ventilating
      Thermodynamics


Distribution Statement : APPROVED FOR PUBLIC RELEASE