The simulation for non-Newtonian fluid has been an important research topic in physically based fluid animation. In this paper, we propose a novel predictive-corrective algorithm for non-Newtonian fluid based on incompressible smoothed particle hydrodynamics (ISPH). First, the viscous liquid is modeled by a non-Newtonian fluid flow and the variable viscosity under shear stress is achieved using a viscosity model known as Cross model. Then, a predictive-corrective method is proposed, by correcting density error with individual stiffness parameters for each particle, to avoid tensile instability and improve numerical stability. Finally, a global adaptive time-stepping method is adopted, which adjusts the time step automatically inde-pendent of the scenario and improve efficiency significantly. The results show that the proposed method can model the Newtonian fluid and the shear thinning non-Newtonian fluid, remove the tensile instability, and simulate in larger time step.%对非牛顿流体的模拟一直是基于物理的流体模拟技术的研究难点.为解决SPH流体模拟中非牛顿流体粒子凝聚成团导致断层现象,提出一种针对剪切变稀型非牛顿流体的预测-校正方法.首先使用Cross模型对流体进行统一建模;然后计算每个流体粒子受到的除了压强力以外的其他力,以此获得中间速度;最后通过求解每个流体粒子的压强系数满足流体的不可压缩性,实现密度校正.为了提高计算速度,该方法使用全局动态时间步长.实验结果表明,文中方法实现了牛顿流体和剪切变稀型非牛顿流体的统一建模,解决了断层问题;相比于无校正方法,其能够在更大的时间步长下稳定运行.
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