Selection of a CF3Br Simulant for Use in Engine Nacelle Certification Tests.
Selection of a CF3Br Simulant for Use in Engine Nacelle
Certification Tests.
(2238 K)
Womeldorf, C. A.; Grosshandler, W. L.
NIST SP 890; Volume 2; Section 12; November 1995.
Fire Suppression System Performance of Alternative
Agents in Aircraft Engine and Dry Bay Laboratory
Simulations. Volume 2, Gann, R. G., Editor(s), 591-621
pp, 1995.
Available from:
National Technical Information Service
Order number: PB96-117783
Keywords:
fire suppression; aircraft engines; nacelle fires;
simulation; halon 1301; halon alternatives; aircraft
certification; pentafluoroethane; sulfur hexafluoride;
boiling point; halon simulants; critical temperature
Abstract:
This section describes the requirements and selection of
a simulant of CF3Br for the purpose of certification
testing engine nacelle fire suppression systems. To
illustrate the storage, delivery, and distribution
requirements of CF3Br, relevant characteristics of
engine nacelle fire suppression systems and
certification tests are briefly summarized. An initial
screening of over 1300 chemicals based on the boiling
point, critical temperature, and molecular weight of
CF3Br is described, and the nine potential candidate
simulants that were found are listed. Three final
candidates (SF6, C2HF5, and CHC1F2) were selected for
experimental testing based upon their saturated vapor
pressures, Jakob numbers, and the requirements of this
application: ozone depletion potential, flammability,
corrosiveness, toxicity, stability and atmospheric
lifetime. To evaluate the hydraulic properties of the
simulants, as compared to CF3Br, pressure traces of
discharges through a piping system into cooled recovery
bottles and to atmosphere are compared with like tests
of CF3Br. To compare the discharge spray distribution
of the simulants with CF3Br, high speed movies of the
plumes at the end of the piping system were taken and
are described. Results and conclusions from comparisons
of the three candidate simulants with CF3Br are
presented and discussed.
