2016-07-282016-07-282016-07-10ICES_2016_161http://hdl.handle.net/2346/67569JapanUnited StatesHokkaido UniversityUniversity of California, Berkeley509ICES509: Fire Safety in Spacecraft and Enclosed HabitatsVienna, AustriaKyosuke Miyamoto, Division of Mechanical and Space Engineering, Hokkaido University, JapanXinyan Huang, Department of Mechanical Engineering, University of California Berkeley, USANozomu Hashimoto, Division of Mechanical and Space Engineering, Hokkaido University, JapanOsamu Fujita, Division of Mechanical and Space Engineering, Hokkaido University, JapanCarlos Fernandez-Pello, Department of Mechanical Engineering, University of California Berkeley, USAThe 46th International Conference on Environmental Systems was held in Vienna, Austria, USA on 10 July 2016 through 14 July 2016.Future space missions may require spacecraft cabin environments different than those used on the International Space Station (ISS). Environmental variables such as flow condition, oxygen concentration, ambient pressure, presence of an external radiant flux, partial or microgravity (µg), may change the material flammability and fire dynamics for any particular set of environmental conditions. Electrical cables and harnesses have been identified as a potential source of fires in spacecraft. In this work, the opposed flame spread behavior for polyethylene (PE) insulated wires are investigated under varying external irradiations and oxygen concentrations. Two wire dimensions with inner copper core/PE insulation outer diameters of 3.5/8.0 mm and 5.5/9.0 mm are selected. Three different insulations: (1) clear high-density (HDPE), (2) clear low-density polyethylene (LDPE), and (3) black LDPE are examined and compared. The work is part of a project in fire safety in space based installations and in particular electrical wire fire safety. The comparison of wire heating by the external radiant flux with core and no core reveals that the copper core acts as a heat sink. Moreover, different PE insulations (i.e. transparence and polymer microstructures) have an appreciable influence on the melting condition and flame spread rate. Phenomenological arguments are used to understand and explain the experimental observations. The result of this work provides information about the fire behavior of electrical wires in fire environments where external heating for an adjacent fire or heat source may be present thus they may be useful toward upgrading the fire safety design and standards of future space missions.application/pdfengFlame Spread RateMeltingPolymer insulationCore thermal conductivitymixed flowPresentation