Droplet Interaction with Hot Surfaces

Abstract

A material's potential fire hazard can be quantified by the rate at which fire spreads over its surface under the influence of forced air convection. If the direction of air flow is the same as the direction of fire propagation, then the fire spread is termed "co-current." If the air flow is opposite to the direction of fire spread, it is termed "countercurrent." The worst-case scenario in a fire would be purely co-current spread. Consequently, several researchers have studied the rate of fire spread under co-current conditions. A question then arises about fire-spread rate under countercurrent conditions. Fire spread over polymethyl methacrylate (PMMA) under counter-current air-flow conditions has been studied. The study was carried out with two different thickness (0.0031 m and 0.0063 m) of PMMA and four different air-speeds (nominally 0.45 m/s, 0.75 m/s, 1.0 m/s and 1.15 m/s). The results indicated that the flame-speed is greater over the thinner sample than over the thicker one. PMMA, commonly called plexiglas or acrylic in fire-spread studies, was used in this study because it has well-defined thermodynamic properties like density, specific heat and heat of combustion and leaves behind little solid residue.

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Document Details

Document Type
Technical Report
Publication Date
Jan 01, 1999
Accession Number
ADA379895

Entities

People

  • Chunming Fu
  • Harsh P. Oke
  • Paul E. Sojka
  • Yudaya Sivathanu

Tags

Communities of Interest

  • Air Platforms

DTIC Thesaurus Topics

  • Air Flow
  • Combustion
  • Engineering
  • Fire Hazards
  • Fires
  • Firing Rate
  • Flow
  • Heat Energy
  • Heat Of Combustion
  • Materials
  • Physical Properties
  • Plastics
  • Polymethyl Methacrylate
  • Resins
  • Specific Heat
  • Thermodynamic Properties
  • Thickness

Readers

  • Combustion and Flow Dynamics.
  • Fluid Dynamics.
  • ballistics.