Transient thermal multiscale analysis for rocket motor case: Mechanical homogenization approach

This paper describes a mechanical homogenization approach to the application of a multiscale formulation for a transient heat transfer problem. The presented formulation evaluates the effective macroscopic thermal properties of composite materials and, by scaling down to the microscale level, provides the microscopic heat flux field by solving elastic problems at the microscopic scale (unit cell). This novel method has the advantage of applying periodic boundary conditions and a uniform macroscopic temperature gradient over the unit cell, which is not easy and often not practical to achieve with heat transfer computation software. The proposed multiscale analysis is verified by various examples of composite materials, and its efficiency is demonstrated on a large-scale problem involving a solid rocket motor.