The dynamics of the Burke-Schumann flame in terms of the Péclet number variation were investigated. The effect of the Péclet number on the flame shape and heat release perturbation in the theoretical study was experimentally confirmed. This number changed through alterations in the average velocity and fuel composition. In addition, the nonlinear effects were reported. These effects were made by different magnitude of velocity oscillation of harmonic frequencies. The effect on the 2nd harmonic frequency is larger when the 1st harmonic flame transfer function showed the lower value. Therefore, the nonlinear characteristics are shown within the range of this study. Also, the specific forcing frequency that makes a non-oscillated flame phenomenon is shown. This frequency makes the very low heat release perturbations and 2nd harmonic oscillations.