Abstract: Ignition-quenching systems include an ignition-risk structure that extends from a support structure into a combustible environment and include a porous ignition-quenching cover that substantially covers the ignition-risk structure. The ignition-quenching cover is configured to quench an ignition event triggered by an ignition source associated with the ignition-risk structure. Ignition-quenching covers generally include a porous body. The porous body may include one or more porous elements. Methods according to the present disclosure include installing a porous ignition-quenching cover over an ignition-risk structure to prevent bulk combustion, e.g., of a fuel vapor in a fuel tank, due to an ignition event associated with the ignition-risk structure.

Abstract: Systems, methods, and apparatuses for triggering electrical arcs are disclosed. Such arcs are useful for testing combustible fluids and equipment operating near ignition hazards. Arcs may be produced with a defined energy at a defined time with little variation in arc energy. Consistent production of arcs is facilitated by one or more of conditioned electrodes, control and/or reduction of parasitic capacitance, avoidance of corona sources, and non-interfering arc triggers. Electrodes may be conditioned by repeated application of conditioning arcs. Conditioned electrodes have relatively physically consistent and chemically consistent tips. Arc triggers may be charged particle sources such as light sources operating in cooperation with a target to produce free electrons proximate the electrodes.

Abstract: Systems and methods for testing ignition properties of particles in a gas. Systems include a test chamber sized to hold a particle to be tested, a gas supply configured to deliver a gas to the test chamber, a heating device configured to heat the particle, and data acquisition equipment configured to collect data associated with the particle and/or the gas. Methods include generating a flow of gas around a particle that is fixed in space relative to the flow of gas in a test chamber, heating the particle and/or heating the gas, and collecting data associated with the particle and/or the gas.

Abstract: Systems, methods, and apparatuses for triggering electrical arcs are disclosed. Such arcs are useful for testing combustible fluids and equipment operating near ignition hazards. In some embodiments, arcs are produced with a defined energy at a defined time with little variation in arc energy. Consistent production of arcs is facilitated by one or more of conditioned electrodes, control and/or reduction of parasitic capacitance, avoidance of corona sources, and non-interfering arc triggers. In some embodiments, electrodes are conditioned by repeated application of conditioning arcs. Conditioned electrodes have relatively physically consistent and chemically consistent tips. In some embodiments, arc triggers are charged particle sources such as light sources operating in cooperation with a target to produce free electrons proximate the electrodes.

Abstract: Systems and methods for ignition source testing with a flammable foam are disclosed. Flammable foam systems and methods for testing use a flammable foam that includes fuel and oxidant. Flammable foam is applied to a test article and an energy discharge is applied to the test article. Methods include determining whether the flammable foam ignited in response to the energy discharge.

Abstract: A method for sealing an interface to attenuate high energy currents and voltages traveling thereacross may include forming a cover defining an inner volume shaped to enclose the interface; forming a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than the semi-rigid sealant; placing the filled sealant within the inner volume; and placing the cover containing the filled sealant over the interface such that the filled sealant is adjacent the interface.

Abstract: Systems and methods for testing ignition properties of particles in a gas. Systems include a test chamber sized to hold a particle to be tested, a gas supply configured to deliver a gas to the test chamber, a heating device configured to heat the particle, and data acquisition equipment configured to collect data associated with the particle and/or the gas. Methods include generating a flow of gas around a particle that is fixed in space relative to the flow of gas in a test chamber, heating the particle and/or heating the gas, and collecting data associated with the particle and/or the gas.

Abstract: A method for sealing an interface to attenuate high energy currents and voltages traveling thereacross may include forming a cover defining an inner volume shaped to enclose the interface; forming a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than the semi-rigid sealant; placing the filled sealant within the inner volume; and placing the cover containing the filled sealant over the interface such that the filled sealant is adjacent the interface.

Abstract: A method for improving conductance on hydraulic fittings by incorporating a soft metal interlayer between the fitting and a hydraulic tube, wherein the soft metal interlayer is located in an area where the fitting engages the hydraulic tube upon swaging or installation under pressure.

Abstract: A seal for attenuating energy from an electrical discharge across an interface may include a cover defining an inner volume containing a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than the semi-rigid sealant such that the filled sealant is adjacent the interface when the cover is placed over said interface. A method for sealing an interface may include forming a cover defining an inner volume shaped to enclose the interface, forming a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than said semi-rigid sealant, placing the filled sealant within said inner volume and placing the cover containing the filled sealant over the interface such that the filled sealant is adjacent the interface.

Abstract: A seal for attenuating energy from an electrical discharge across an interface may include a cover defining an inner volume containing a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than the semi-rigid sealant such that the filled sealant is adjacent the interface when the cover is placed over said interface. A method for sealing an interface may include forming a cover defining an inner volume shaped to enclose the interface, forming a filled sealant including a semi-rigid sealant mixed with a filler having a multiplicity of discrete particles of different composition than said semi-rigid sealant, placing the filled sealant within said inner volume and placing the cover containing the filled sealant over the interface such that the filled sealant is adjacent the interface.

Abstract: A method for improving conductance on hydraulic fittings by incorporating a soft metal interlayer between the fitting and a hydraulic tube, wherein the soft metal interlayer is located in an area where the fitting engages the hydraulic tube upon swaging or installation under pressure.

Abstract: A method, apparatus, and composite fuel tank for manufacturing a structure is provided. A first composite layer and a second composite layer are placed on a mold. The second composite layer and the first composite layer are cured. The first composite layer and the second composite layer form the structure. The second composite layer is configured to dissipate an electric charge on a surface of the structure.

Abstract: Methods and systems for discriminating among sparking modes are disclosed. In one embodiment, a method includes receiving light from a spark into a spectrometer, generating a light intensity spectrum using the spectrometer, and classifying the sparking mode based on an analysis of the light intensity spectrum. The light intensity spectrum may be analyzed for the presence of an atomic emission and a broad blackbody emission. In further embodiments, light emitted by the spark may be received into a photodetector, and the classification of the sparking mode may be based on an analysis of an intensity profile, including at least one of a rise-time phase, a peak intensity, and a drop-off phase.

Abstract: Methods and systems for discriminating among sparking modes are disclosed. In one embodiment, a method includes receiving light from a spark into a spectrometer, generating a light intensity spectrum using the spectrometer, and classifying the sparking mode based on an analysis of the light intensity spectrum. The light intensity spectrum may be analyzed for the presence of an atomic emission and a broad blackbody emission. In further embodiments, light emitted by the spark may be received into a photodetector, and the classification of the sparking mode may be based on an analysis of an intensity profile, including at least one of a rise-time phase, a peak intensity, and a drop-off phase.