R.E. Blumke

A cargo compartment facility was utilized for two cargo fire tests. The objective of the 2nd test was to assess fire containment and fire extinguishment in the cargo by reducing the ventilation through the cargo compartment. Parameters which were measured included ignition time, burnthrough time and physical damage to the cargo liner, composition of selected combustible gages, temperature time histories, heat flux and detector response. The ignitor load was made of a typical cargo consisting of filled cardboard cartons occupying 50% of the compartment volume. Test data and test results are discussed for both tests.

James E. Demaree

Laboratory evaluations were performed to determiine the flame characteristics of the Lennox OB-32 conversion oil burner. Three commericially available burenrs were modified to produce a flame with characteristics similar to the Lennox OB-32. Various apparatus used in this determination are described in this report. It was concluded that the three burners tested could be modified to produce flame patterns and characteristics comparable to the Lennox OB-32 conversion oil burner.

The burner described inthis report has been used to determine the fire resistance of flexible hose assemblies under simulated conditions. The test was aimed at producing a typical aircraft powerplant fire.

R.J. Mannheimer

Two different rheological phenomena have been studied that may relate to the mechanisms by which high molecular weight polymers inhibit misting. The first of these is a shear thickening or antihixotripic in which the liquid fuel develops a shear induced structure above a critical shear stress. The second phenomena involves the sudden increase in resistance to flow in porous media that certain polymer solutions exhibit when the flow rate is above a critical value. This effect is quite different form the first in that the former can be induced by shear while the latter requires elongation. While it is difficult to interpret these phenomena directly in terms of shear and elongational viscosities, it appears possible that the critical shear stress and the critical flow rate may be useful criteria for characterizing the condition of the antimist additive.

The theoretical significance of the critical flow rate in porous media has been discussed in terms of a fluid relaxation time which in turn may be related to the polymer molecular weight. A relationship between the critical flow rate and the intrinsic viscosity is presented that explains why former is more sensitive to polymer degradation.

Carlos J. Hilado

ABSTRACT: The thermochemical and flammability characteristics of some typical thermoplastic materials currently in use and others being considered for use in aircraft interiors are described. The properties studied included (1) thermomechanical properties such as glass transition and melt temperature, (2) changes in polymer enthalpy, (3) thermogravimetric analysis in anaerobic and oxidative environments, (4) oxygen index, (5) smoke evolution, (6) relative toxicity of the volatile products of pyrolysis, and (7) selected physical properties. The generic polymers that were evaluated included: acrylonitrile butadiene styrene, bisphenol A polycarbonate, 9,9 bis (4-hydroxyphenyl) fluorene polycarbomite-poly (dimethylsiloxane) block polymer, phenolphthalein-bisphenol A polycarbonate, phenolphthalein polycarbonate, polyether sulfone, polyphenylene oxide, polyphenylene sulfide, polyaryl sulfone, chloril]ated polyvinyl chloride homopolymer, polyvinyl fluoride, and polyvinylidene fluoride. Processing parameters, including molding characteristics of some of the advanced polymers, are described. Test results and relative rankings of some of the flammability, smoke, and toxicity properties are presented. Under these test conditions, some of the advanced polymers evaluated were significantly less flammable and toxic or equivalent to polymers in current use.

C.E. Polymeropoulos, V. Sernas

The droplet size distribution in various experimental air-fuel sprays was measured using a holographic method. There was good agreement between upper-limit log-normal velocity distribution functions and the droplet size data. The Sauter mean diameter, maximum droplet diameter, and air-fuel ration were also well represented by the area data. Measurements of burning velocities in the sprays tested were compared with calculated predictions, and the modified fuel sprays produced under wind shear conditions were also calculated.