The deposition rate and uniformity in CVD reactors are function of transport phenomena. A mathematical model including the coupled mass transfer with hydrodynamics and heat transfer has been developed to predict reactant concentrations, flow patterns and temperature fields in a cold wall CVD reactor. The model consists of the partial differential equations describing the balance of mass, momentum, heat and species concentration and variable gas properties. The equations are solved numerically in two-dimensional, axisymmetric form using a control-volume-based finite difference technique. The model is applied to growth of silicon carbide layers obtained by LPCVD from the pyrolysis of tetramethylsilane. We present computed temperature, velocity and TMS concentration profiles. We compare predicted deposition rates with experimental result