A solution via generalised intergral transform technique for the simultaneous transport processes during combustion of wood cylinders

A non-linear moving boundary di usion problem is proposed as a simple model for the heat transfer during combustion of wood cylinders. Such a problem is solved here by applying the generalized integral transform technique. A new ltering strategy, denoted as local-instantaneous lter, is used in order to accelerate the convergence of the series-solution obtained with the present hybrid numerical{analytical technique. We show that the use of such ltering approach reduces the sti ness of the system of ordinary di erential equations, resultant from the integral transformation of the original problem. Hence, subroutines based on simpler and faster methods can be used for the solution of such systems. Results are presented in the paper for the combustion of cylinders of di erent sizes and involving di erent initial moisture contents and densities. The e ects on the solution of di erent models available in the literature for the evaluation of thermal conductivity and speci c heat are also addressed on the paper.