Radiant-Energy Penetration Effect in the Thermal-Diffusivity Flash Technique for Layered and Porous Polymers,
Abstract
Thermal insulation characterization of polymers and other materials is an important requirement for present and future aerospace missions, as well as for the home construction industry. Some dispersed composites and layered samples have been successfully characterized by the thermal-diffusivity flash technique, while the interpretation of these and other experiments for systems remains problematical. One refinement for layered-sample data reduction is investigated here. An exponentially decaying spatial penetration of radiant energy into the sample is accounted for. Under the conditions chosen for numerical evaluation and 18% reduction in the backface rise time, t1/2, is predicted for a case in which on 5% as much radiant energy is deposited on the midplane as on the front surface. It is experimental methods of estimating the penetration depth of the radiant energy for particular samples. Keywords: Laplace transform; Heat conduction problem; Equations; and Slabs. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Dec 02, 1985
- Accession Number
- ADA162508
Entities
People
- Robert S. Bretzlaff
Organizations
- The Aerospace Corporation