Ji Chenzhen, Zhao Dan
Aerospace Engineering Division, College of Engineering, Nanyang Technological University, 50 Nanyang Avenue, Singapore 639798, Singapore.
J Acoust Soc Am. 2014 Jun;135(6):3243-51. doi: 10.1121/1.4876376.
In this work, three-dimensional numerical simulations of acoustically excited flow through a millimeter-size circular orifice are conducted to assess its noise damping performance, with particular emphasis on applying the lattice Boltzmann method (LBM) as an alternative computational aeroacoustics tool. The model is intended to solve the discrete lattice Boltzmann equation (LBE) by using the pseudo-particle based technique. The LBE controls the particles associated with collision and propagation over a discrete lattice mesh. Flow variables such as pressure, density, momentum, and internal energy are determined by performing a local integration of the particle distribution at each time step. This is different from the conventional numerical investigation attempting to solve Navier-Stokes (NS) equations by using high order finite-difference or finite-volume methods. Compared with the conventional NS solvers, one of the main advantages of LBM may be a reduced computational cost. Unlike frequency domain simulations, the present investigation is conducted in time domain, and the orifice damping behavior is quantified over a broad frequency range at a time by forcing an oscillating flow with multiple tones. Comparing the numerical results with those obtained from the theoretical models, large eddy simulation, and experimental measurements, good agreement is observed.
在这项工作中，对通过毫米尺寸圆形孔口的声学激励流进行了三维数值模拟，以评估其噪声衰减性能，特别强调应用格子玻尔兹曼方法（LBM）作为一种替代的计算气动声学工具。该模型旨在通过使用基于伪粒子的技术来求解离散格子玻尔兹曼方程（LBE）。LBE控制与离散格子网格上的碰撞和传播相关的粒子。诸如压力、密度、动量和内能等流动变量是通过在每个时间步对粒子分布进行局部积分来确定的。这与试图通过使用高阶有限差分或有限体积方法来求解纳维-斯托克斯（NS）方程的传统数值研究不同。与传统的NS求解器相比，LBM的主要优点之一可能是计算成本降低。与频域模拟不同，本研究是在时域中进行的，并且通过用多个音调强迫振荡流，一次在很宽的频率范围内对孔口的阻尼行为进行量化。将数值结果与从理论模型、大涡模拟和实验测量中获得的结果进行比较，观察到了良好的一致性。
