- Author
- Leonard, J. T. | Fulper, C. R. | Darwin, R. L. | Back, G. G. | Quellette, R. J. | Scheffey, J. L. | Willard, R. L.
- Title
- Post-Flashover Fires in Simulated Shipboard Compartments. Phase 2. Cooling of Fire Compartment Boundaries.
- Coporate
- Naval Research Lab., Washington, DC Naval Sea Systems Command, Washington, DC Hughes Associates, Inc., Wheaton, MD
- Report
- NRL Memorandum 6896, September 19, 1991, 44 p.
- Distribution
- Available from National Technical Information Service
- Keywords
- compartment fires | fire spread | flame spread | flashover | shipboard fires | fire tests | fire simulation | cooling | JP-5 jet fuel | fuel sprays | water sprays | nozzles | application rate | bulkheads | surface temperature | spray nozzles
- Identifiers
- post-flashover; fire boundaries
- Abstract
- A series of fire tests was conducted in simulated shipboard compartments to evaluate the effectiveness of various compartment cooling techniques in preventing the spread of fire both horizontally and vertically. The compartments were steel cubes, 2.4 x 2.4 x 2.4 m(8 x 8 x 8 ft), arranged such that the fire compartment was in the center with two cubes on either side and one compartment was directly overhead. All compartments were instrumented with thermocouples and heat flux transducers. The fire threat was a 2 gpm JP-5 fuel spray fire to simulate instant flashover of the fire compartment. Both manual and installed water spray nozzles were evaluated for cooling efficiency. An application rate of 2.04 lpm (0.05 gpm/ft(2)) was found to be the minimum required to cool both horizontal and vertical compartment boundaries to 100 deg C (212 deg F). Although cooling of horizontal boundaries was not affected by application technique, cooling of vertical boundaries was highly dependent on technique. Maximum cooling of vertical boundaries was achieved by applying water tangentially to the boundary surface in sheets or large droplets with nozzles that produce a fan shaped water spray pattern. Maximum cooling was achieved when the nozzle was oriented to provide complete coverage of the bulkhead by the water spray pattern, and the water droplets remained on the heated surface for a sifficient time to absorb the heat. Full cone nozzles spraying perpendicular to the heated surface provided some cooling for medium size droplets at higher application rates, while fine atomizing nozzles did very little to reduce the builhead surface temperature.