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):

Report Date:

1992-08-01

Pagination or Media Count:

95.0

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.

Subject Categories:

  • Physical Chemistry
  • Air Conditioning, Heating, Lighting and Ventilating
  • Thermodynamics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE