Characterization of Forced Convection Heat Transfer in Decomposing, Glass-Filled Polymer Composites

Abstract

An experimental study has been conducted to estimate volumetric heat transfer coefficients between product volatiles and the .solid matrix within the tortuous pore network of decomposing glass-filled polymer composites. Two such composite materials, denoted as Haveg H41N and Fiberite MXBE-350, have been studied in this experimental investigation. For both materials, volumetric heal transfer coefficients were measured between argon gas and the pore network of 0.17 cm thick specimens precharred to 25°C (virgin specimens), 500°C, 600°C and 800°C, at several gas flow rates. For H41N, gas pressure drop values ranging from 3.45 times 104 Pa to 1.72 times 105 Pa, for each stage of decomposition, were imposed to create flow through the pore network. Gas pressure drop values for MXBE-350 ranged from 6.89 times 103 Pa to 6.89 times 104 Pa. In both cases the volumetric heat transfer coefficients were found to be dependent on stage of decomposition and gas pressure drop across the specimen, i.e., gas flow rate. This behavior has been modeled using a modified correlation in the form of a Nusselt number as a function of Reynolds number. Correlated and experimental results are presented graphically.