The effect of Stokes number on the kinetic energy(KE)budget in particle-laden turbulent channel flows is examined by conducting two-way coupled direct numerical simulations using the Eulerian-Lagrangian approach.The friction Reynolds number of the single phase channel flow is Reτ=180,the particle mass loading and volume fraction are φm=0.2,φv ≈ 10-4,and the Stokes numbers range from St+=14-92.The statistics show that due to the presence of solid particles,the mean velocity is reduced in the vicinity of the wall but enhanced in the outer region,and the off-streamwise intensity of fluctuated velocity and the Reynolds stress are reduced in the whole channel.The analysis on the budgets of turbulent kinetic energy(TKE)finds that the presence of particles induces a significant reduction on both the production and dissipation rates.With increasing Stokes number St+,both the production and dissipation rates exhibit non-monotonical trends,i.e.,both initially decrease for St+＜40 and then transit to growth after St+＞40.This suggests that the particle-induced suppression on TKE production and dissipation is the strongest nearly at St+=40.It is also found that particles act as an additional sink/source term in the budgets of both mean-flow kinetic energy(MKE)and TKE.In addition,we investigate the influence of St+on the"zero point"which indicates the balance of exchanging energy between the particle and fluid phases.It is shown that with increasing St+,the"zero point"moves toward the wall,suggesting that the position of perfect following between particle and fluid is closer to the wall with larger St+.The present results reveal the Stokes number effects on the spatial transport mechanisms of MKE,TKE in turbulent channel flows laden with inertial particles.

Zhi-feng Wu;Jian-zhao Wu;Bo-fu Wang;Zhi-ming Lu

Shanghai Institute of Applied Mathematics and Mechanics,School of Mechanics and Engineering Science,Shanghai Key Laboratory of Mechanics in Energy Engineering,Shanghai University,Shanghai 200072,China

水动力学研究与进展B辑

[1]Zhi-feng Wu;Jian-zhao Wu;Bo-fu Wang;Zhi-ming Lu-.Effect of Stokes number on energy modulation of the fluid in turbulent particle-laden channel flows)[J].水动力学研究与进展B辑,2022(03):510-521

St+,monotonical,St+on

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