弹性颗粒声散射问题直接模拟的IB-LBM研究

Direct simulation of acoustic scattering problem of elastic particles using improved IB-LBM

针对弹性颗粒声散射问题提出了一种基于改进IB-IBM的直接模拟方法。在该模拟方法中,流体采用格子Boltzmann方法(LBM)求解,固体采用光滑点插值法(S-PIM)求解,流固耦合采用浸入式边界方法(IBM)处理,声场通过计算求得的流场压力瞬时扰动直接获得。通过二维近似刚性颗粒声散射算例,该方法得到初步验证;与此同时,计算了二维弹性颗粒声散射问题,讨论了颗粒弹性,声传播介质类型对散射声场的影响,进一步验证了该方法的有效性。

An improved immersed boundary-lattice Boltzmann method(IB-LBM)was proposed for direct simulation of acoustic scattering problem of elastic particles.Using this method,a fluid domain was solved with LBM,a solid domain was solved with the smooth point interpolation method(S-PIM),fluid-structure interaction(FSI)was handled with the immersed boundary method(IBM)and an acoustic field was obtained with the fluid field pressure instantaneous perturbation calculated.The proposed method was preliminarily verified with the simulation of an acoustic scattering example of 2-D nearly rigid particles.At the same time,acoustic scattering of elastic particles was also simulated.Effects of particle elasticity and type of sound propagation medium on scattered sound field were investigated to further verify the effectiveness of the proposed method.