Identification of spectral radiative properties of closed cell polymeric foams using coupled Monte Carlo-particle swarm optimization

Abstract

An inverse radiation analysis is performed for identification of spectral radiative properties for a class of highly porous closed cell polymeric foams using coupled Monte Carlo-Particle Swarm Optimization method. An Open Message Passing Interface (MPI) based parallel Monte Carlo method is adopted to simulate thermal radiation within the foam. The Particle Swarm Optimization (PSO) with adaptive weighted delay velocity is employed to inversely identify the spectrally dependent transport extinction coefficient and scattering albedo of expanded polystyrene and polyethylene foams from measured spectral transmittance. The transmittance measurements were performed with a Fourier-transform infrared spectrometer across the IR wavelength range of 2.0–16.7 μm. The developed inverse model used transmittance measurements of two samples of the same foam having different thicknesses to successfully retrieve the unknown radiative parameters of the foams. Both of the foams demonstrated consistently high transport extinction coefficients at all wavelengths in a range of 6400–400 m−1. Spectral transport scattering albedos of both the foams were discovered to be in the range 0.70–1.0. The accuracy of the proposed inverse model is checked by numerically predicting the spectral transmittances for a third sample of different thickness using the retrieved radiative properties. A good agreement is observed between the experimental and the numerically predicted transmittance values for the third thickness.