Lattice Boltzmann simulation of particle-laden turbulent channel flow
Lattice Boltzmann simulation of particle-laden turbulent channel flow
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DOI：
10.1016/j.compfluid.2015.07.008
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发表时间：
2016-01
影响因子：
2.8
通讯作者：
Lian-Ping Wang;Cheng Peng;Zhaoli Guo;Zhaosheng Yu
中科院分区：
文献类型：
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作者：
Lian-Ping Wang;Cheng Peng;Zhaoli Guo;Zhaosheng Yu
有限尺寸固体颗粒对载相湍流的调制与许多工业和环境应用有关。在这里，我们报告的颗粒分辨模拟的湍流槽道流动充满了有限尺寸的固体颗粒。我们讨论了如何介观格子玻尔兹曼方法（LBM）可以应用于处理湍流载流和移动的流体-颗粒界面。为了验证LBM方法，我们首先模拟了摩擦雷诺数为180的单相湍流槽道流。设计了一个非均匀力场来激发湍流脉动。由此产生的平均流量剖面和湍流统计被认为是在很好的协议与已公布的数据的基础上的切比雪夫谱方法。我们还发现，充分发展的湍流槽道流的统计是独立的LBM方法中的一些松弛参数的设置。然后，我们考虑了相同的体积力下的颗粒负载的湍流槽道流。粒子具有与流体相同的密度。颗粒直径为通道宽度的5%，平均体积分数为7.09%。我们发现，颗粒的存在下，平均流速降低了4.6%，这意味着流体-颗粒系统比单相流更耗散。平均流速的最大局部减小约为7.5%。固体颗粒对流体均方根速度波动的影响是混合的：根据相对于通道壁的方向和空间位置，观察到减少和增加。总的来说，颗粒增强了近壁区的相对湍流强度，抑制了中心区的相对湍流强度。通道内的颗粒浓度分布也比较复杂。我们发现，有一个动态的平衡位置类似的Segmente-Silberberg效应已知的层流壁有界流动。我们的LBM结果被认为是在良好的协议与结果的基础上的有限差分方法与直接迫使处理移动的固体颗粒。此外，阶段划分的统计数据，获得和比较。
Modulation of the carrier phase turbulence by finite-size solid particles is relevant to many industrial and environmental applications. Here we report particle-resolved simulations of a turbulent channel flow laden with finite-size solid particles. We discuss how the mesoscopic lattice Boltzmann method (LBM) can be applied to treat both the turbulent carrier flow and moving fluid-particle interfaces. To validate the LBM approach, we first simulate the single-phase turbulent channel flow at a frictional Reynolds number of 180. A non-uniform force field is designed to excite turbulent fluctuations. The resulting mean flow profiles and turbulence statistics were found to be in excellent agreement with the published data based on the Chebychev-spectral method. We also found that the statistics of the fully-developed turbulent channel flow are independent of the setting of some of the relaxation parameters in the LBM approach. We then consider a particle-laden turbulent channel flow under the same body force. The particles have the same density as the fluid. The particle diameter is 5% of the channel width and the average volume fraction is 7.09%. We found that the presence of the particles reduces the mean flow speed by 4.6%, implying that the fluid-particle system is more dissipative than the single-phase flow. The maximum local reduction of the mean flow speed is about 7.5%. The effects of the solid particles on the fluid rms velocity fluctuations are mixed: both reduction and augmentation are observed depending on the direction and spatial location relative to the channel walls. Overall, particles enhance the relative turbulence intensity in the near wall region and suppress the turbulence intensity in the center region. The particle concentration distribution across the channel is also complicated. We find that there is a dynamic equilibrium location resembling the Segŕe–Silberberg effect known for a laminar wall-bounded flows. Our LBM results were found to be in good agreement with results based on a finite-difference method with direct forcing to handle the moving solid particles. Additionally, phase-partitioned statistics are obtained and compared.