DIRECT SIMULATIONS OF CAVITY TONES BY THE FINITE DIFFERENCE LATTICE BOLTZMANN METHOD

摘要

We performed a direct simulation of two-dimensional cavity tone by the finite difference lattice Boltzmann method. The Mach number of the flow is 0.2, and the Reynolds number is . Sound emission is mainly simple-source like but some non-isotropic nature is detected especially in the near field. It is found that when the cavity emits the positive pressure sound of which the pressure is higher than the ambient pressure, the whole region inside the cavity becomes positive. The pressure drops after the emission and the negative pressure sound is emitted. The relationship between the flow inside the cavity and the sound emission is clarified. Turbulent flow simulation gives almost the same results. 8 5.5 10 ×