Document Type : Research Paper
University of Kashan
PACE Company, No.20, Pirouzan St., North Sheikh Bahaei Ave., Tehran, Iran
In chemical engineering, several processes are represented by singular boundary value problems. In general, classical numerical methods fail to produce good approximations for the singular boundary value problems. In this paper, Chebyshev finite difference (ChFD) method and DTM-Pad´e method, which is a combination of differential transform method (DTM) and Pad´e approximant, are applied for solving singular boundary value problems arising in the reaction cum diffusion process in a spherical biocatalyst. ChFD method can be regarded as a non-uniform finite difference scheme and DTM is a numerical method based on the Taylor series expansion, which constructs an analytical solution in the form of a polynomial. The main advantage of DTM is that it can be applied directly to nonlinear ordinary without requiring linearization, discretization or perturbation. Therefore, it is not affected by errors associated to discretization. The results obtained, are in good agreement with those obtained numerically or by optimal homotopy analysis method.