The application of azimuthal acoustic forcing to flames in a laboratory scale annular combustor is demonstrated in the present paper, which not only allows large amplitude azimuthal modes to be excited, but permits control to be exerted over their frequency, amplitude, and their modal dynamics, including parameters such as the spin ratio and orientation. The effect of forcing frequency is investigated, and it is found that the excitation can be well controlled into a standing wave oscillation over a range of amplitudes for selected frequencies. However, close to the natural frequency of the system, the modal dynamics cannot be well controlled, and instead these tend towards their self-excited state, resulting in a mixed mode. Comparing the phase-averaged structure of the forced and self-excited responses for similar operating conditions, illustrate similar flame dynamics, making this novel forcing approach extremely useful for the study of these instabilities in annular systems.

本文演示了在实验室规模的环形燃烧器中将方位角声强迫应用于火焰的方法，该方法不仅可以激发大振幅的方位模态，还可以对其频率，振幅及其模态动力学进行控制，包括旋转比和方向等参数。研究了强迫频率的影响，发现对于选定的频率，可以在一定幅度范围内将激励很好地控制成驻波振荡。但是，接近系统的固有频率时，模态动力学无法得到很好的控制，相反，它们趋向于它们的自激状态，从而导致混合模式。比较类似工况下强迫和自激响应的相位平均结构，