Numerical study of the influence of bichannel-system geometry on the existence domain of Hartmann effect
A.A. Zhilin1,2, A.V. Primakov1,2
1Khristianovich Institute of Theoretical and Applied Mechanics SB RAS, Novosibirsk, Russia
2Siberian State University of Water Transport, Novosibirsk, Russia
Keywords: Hartmann generator, high-intensity acoustic oscillations, wave processes, gas-dynamic resonance, off-design jet
Abstract
The present numerical study is aimed at revealing the influence of the distance between the nozzle exit and the resonator edge 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 the physical processes in the flow path of multichannel systems that generate high-intensity acoustic fields. Five configurations of the bichannel system were considered, where the gap was 0.85, 1.10, 1.35, 1.60, and 1.85 of the resonator diameter. As a result of the study, a complete picture of the gas-dynamic flow formed in the flow path of the bichannel system was obtained, including the resonating cavity and the region in between the nozzle and the 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 by other authors. Subsequent increase in the distance between the nozzle and the resonator leads to the emergence of subharmonics and multiple harmonics. Verification of gained numerical results with known experimental data is carried out.
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