The present numerical study is aimed at revealing the influence of the nozzle exit-to-resonator edge distance on the gas-dynamic characteristics of the acoustic-convective flow in the flow path of a bichannel system. The aim of the work is the development of a computational technology for describing physical processes in the duct of multichannel systems that generate high-intensity acoustic fields. Five configurations of the bichannel system in which the gap between the nozzle exit and the resonator edge was 0.85, 1.10, 1.35, 1.60, and 1.85 of the resonator diameter, were analyzed. As a result of the study, a complete picture of the gas-dynamic flow formed in the duct of the bichannel system was obtained, including the resonating cavity and the region in between the nozzle and resonator. With the help of numerical simulation, the formation of a flow with high-frequency, low-amplitude oscillations at a small gap between the nozzle exit and the resonator edge, which was observed in experiments, has been demonstrated. Pure-tone oscillations with maximum intensity occur when the resonator is placed in the region of the beginning of the second barrel, this observation being in good agreement with the data obtained by other authors. Subsequent increase in the nozzle-to-resonator distance leads to the emergence of subharmonics and multiple harmonics. Verification of gained numerical results with available experimental data is carried out.

本数值研究旨在揭示喷嘴出口到谐振器边缘距离对双通道系统流路中声对流流动的气体动力学特性的影响。这项工作的目的是开发一种计算技术，用于描述产生高强度声场的多通道系统管道中的物理过程。分析了双通道系统的五种配置，其中喷嘴出口和谐振器边缘之间的间隙为谐振器直径的 0.85、1.10、1.35、1.60 和 1.85。研究结果是，获得了双通道系统管道中形成的气体动力流动的完整图像，包括谐振腔以及喷嘴和谐振器之间的区域。借助数值模拟，实验中观察到，在喷嘴出口和谐振器边缘之间的小间隙处形成了高频、低振幅振荡的流动。当谐振器放置在第二个桶的起始区域时，会出现最大强度的纯音振荡，这一观察结果与其他作者获得的数据非常一致。随后喷嘴到谐振器距离的增加导致分谐波和多重谐波的出现。用可用的实验数据验证了所得的数值结果。