气固两相湍流非定常压力脉动特性数值模拟研究OACSTPCD

Relevant to thermoacoustic combustion instability in engines,the pressure oscillations in gas-solid two-phase turbulent flow have long been a topic of great concerns.To understand the pressure oscillation characteristics in gas-solid two-phase flow,three-dimensional unsteady numerical calculations are conducted for typical two-phase gas-solid backstep flow using the combined self-adaptive turbulence eddy simulation(SATES)and discrete phase model(DPM)method.The accuracy and reliability of the numerical method is firstly validated by comparisons with the experimental data.Then,the unsteady pressure signal of the two-phase gas-solid flow is compared with that of the pure gas phase flow,and it is found that with the addition of solid particles,the dominant frequency of pressure oscillation is slightly changed,and the oscillation amplitude significantly decreases.Finally,the effects of diameter and mass fraction of solid particles on the pressure oscillation are investigated.It is found that with increasing the solid particle diameter,the amplitude of pressure oscillation firstly decreases and then increases,and the amplitude exhibits the smallest with the diameter of 10 μm;with increasing the mass fraction of solid particle,the pressure oscillation amplitude shows a decreasing trend.The results demonstrate that the properties of solid particles in two-phase flow have a small impact on the dominant frequency of pressure oscillation,while a significant impact on the oscillation amplitude.