The combustion of Helmholz-type combustor was simulated using computational fluid dynamics (CFD) method. The unsteady-state Reynolds-averaged Navier Stokes method, standard k-ε turbulence model and eddy dissipation combustion model was applied to the CFD model to simulate fluctuations in the combustion chamber, tailpipe and outlet. The prediction showed agreement with experimental results which proved that the frequencies of pressure, velocity and heat release of tail gas were accordant to the pressure frequency in the combustion chamber. The simulations were perfected for an experimental combustor, and it has built up a solid base for further investigation on applications to a large scale dryer.