AAAR 32nd Annual Conference
September 30 - October 4, 2013
Oregon Convention Center
Portland, Oregon, USA
Abstract View
Validation of the Moment Method for Determining Smoke Aerosol Properties in Space
MARIT MEYER, George Mulholland, David Urban, Gary Ruff, Zeng-guang Yuan, Victoria Bryg, Thomas Cleary, Jiann Yang, NASA Glenn Research Center
Abstract Number: 423 Working Group: Combustion
Abstract Characterizing smoke aerosols in space is difficult due to limitations on the weight and complexity of instruments that can be deployed. However, advances in spacecraft fire safety depend on identifying likely fire sources and characterizing smoke from these materials. Investigations of these smoke aerosols in low gravity provide important design input for the development of future space fire detectors. The Smoke Aerosol Measurement Experiment (SAME) employed three basic aerosol instruments to measure different moments of the smoke particle size distribution for five common spacecraft materials. The count mean diameter of the smoke particles and the diameter of average mass are calculated from these moment averages. Furthermore, the geometric mean diameter and geometric standard deviations can be calculated if the particle size distribution is assumed to be lognormal. Validation of this characterization method has been performed in a set of experiments using the SAME smoke-generating hardware and the returned flight aerosol instruments. A Scanning Mobility Particle Sizer Spectrometer (SMPS) is too large and complex to include in a space flight experiment, but its use in ground-based testing determined whether the log-normal assumptions were valid, and provided high-resolution particle size distributions of the smoke from each material. SMPS particle size distributions from ground experiments are compared to particle statistics generated by moment calculations and particle size distributions from microscopic analysis of TEM images of particles for both un-aged and aged smoke.