A partial differential model for the pyrolysis of materials with movable residual layer

Due to the existence of nonlinear mobile boundary conditions in the pyrolysis process of charring materials, such as the insulating layers of wires and cables, the precise tracing of the pyrolysis surface and calculating the pyrolysis rate pose a great challenge for researchers when trying to model the process using partial differential models. In this paper, the direct numerical simulation method including a set of partial differential equations has been exerted to make detailed studies on the pyrolysis of materials with changeable residual layers. In the simulation, a movable domain model was transformed to a fixed domain model and a cyclic iterative method was adopted to predict the thermal interface location between pyrolysis zone and virgin material. Resulting numerical results show good correlations with the exact solutions and the results of an integral model. In addition, influences of the residue mass ratio of the charring layer on the evolution of pyrolysis rate of the polyethene material with the time were also investigated. Copyright © Taylor & Francis Inc.