中文摘要：

本文采用直接数值模拟的方法，研究了颗粒惯性对均匀各向同性湍流场中被动标量混合特性的影响。结果表明；与无颗粒算例相比，Tp／Tk《1的小颗粒，增大了标量脉动在高波数上的能量，增强了标量耗散率，标量耗散率最大高出了25％；Tp／Tk》1的大颗粒，在初期显著削弱了标量脉动强度，同时也加快了标量耗散率的衰减，标量脉动强度降低了约15％，标量耗散减少了约5％；而Tp／Tk=1的临界颗粒，对标量场混合的影响较弱，标量脉动强度和标量耗散偏差在5％以内；此外，随着颗粒惯性的增大，标量耗散率的概率密度函数向左平移，但分布特征的改变并不显著。

英文摘要：

The influence of partial inertia on scalar mixing in homogeneous isotropic turbulent flows was studied using a direct numerical simulation （DNS） method. The results show that, compared with the case without particle, micro-particle increases the high wavenumber values of scalar variance spectrum and most of 25% scalar dissipation; larger particle decreases scalar variance at the initial stage of simulation remarkably, and accelerates the decay rate of scalar dissipation, the scalar variance and dissipation was mostly lower than that of the case without particle 15% and 5% respectively; critical particle, however, has not obvious influence on scalar mixing in our simulation, the deviation of the scalar fluctuation and dissipation rate was less than 5%. Also with the increasing of particle inertia, probability density distributions of scalar dissipation shift toward left, but the characteristics of these PDFs were of few changes.