Response of Layered Structures to Thermal Radiation Pulses

摘要

An approximation to the response of composite or layered structures to thermal radiation from a nuclear device was developed. The model developed uses the Extrapolated Crank-Nicolson unconditionally stable implicit finite difference scheme to approximate the nonlinear parabolic partial differential heat transfer equation. The model allows for convection at the front face and assumes the back face is insulated. The model assumes one-dimensional heat conduction in Cartesian coordinates. The program approximates Glasstone's thermal pulse shape and uses it and two different moments-matched pulses for the incident thermal radiation. The program was used to do a sensitivity analysis of pulse shape on response. The program uniquely handles the interface conditions to match the Crank-Nicolson accuracy and stability. The program was developed to be run for various thermal fluences and weapon yields. The results showed that the early transients are dependent on pulse shape. The temperature profile in the structure at the approximate time of blast arrival was not dependent on pulse shape however. It was also shown that the nonlinearity affected the peak temperature at the front face. Theses. (mjm)