B109 音響励振下における噴流の蛇行現象の数値解析

抄録

Fluid-dynamical behavior of a jet exposed to sound waves is investigated by means of numerical simulation. Unsteady, three-dimensional, compressible Navier-Stokes equation including gravity term is solved with NSCBC (Navier-Stokes characteristic boundary condition). In order to simplify the computation by avoiding the calculation for chemical species, the jet of methane gas used in the experiments is replaced by a jet of hot air having the same density of the methane at the room temperature. The results of the calculation showed that the jet meanders negligibly at 110 dB in sound pressure level, although the experiments at the same level shows clear meandering structure followed by bifurcation. Notable meandering behavior appeared at 150 dB, impracticably high level. Shadowgraph images produced from the numerical results showed some analogous characteristics to those of the experiments.