The Belousov-Zhabotinskii reaction in an annular gel reactor [Z. Noszticzius et al., Nature 329, 619 (1987)] is modeled by the reduced two-variable Oregonator with radial gradients in the concentration of bromate and malonic acid. This model is found to produce a wave shape and dispersion relation that are in satisfactory agreement with the experimental data. The numerical studies also reveal that the pinwheel dynamics can be understood in terms of the local chemistry in the reactor. © 1991 American Institute of Physics.