中文摘要：

作为一充分 Lagrangian，基于粒子的数字方法，传统的弄平的粒子水动力学(SPH ) 通常受不了精确性问题。调查这个数字错误的物理起源，在 SPH 粒子之间的有弹性的效果被类比明确地与物理实体，和一个唯一的非维的数字识别被建议评估相对优势对有弹性的效果粘滞。通过二维的 Couette 流动的模拟，粒子的速度侧面和安排为各种各样的比率被检验对有弹性的效果粘滞。当这个非维的数字增加， SPH 粒子的有效粘性减少，当粒子数字的增加显著地仅仅在更低的比率减少有效粘性时对有弹性的效果粘滞。不同在之中名字粘滞驱散，全部的驱散，和理论驱散进一步证实 unphysical 驱散源于有弹性的效果的存在。在摘要，由于从马赫数字和比率的限制对有弹性的效果粘滞，在那里存在牛顿的行为能是的一个批评雷纳兹在下面数字近似通过模型参数的合适的选择获得了。

英文摘要：

As a fully Lagrangian, particle-based numerical method, the traditional smoothed particle hydrodynamics （SPH） generally suffers from the accuracy problem. To investigate the physical origins of this numerical error, the elastic effect between SPH particles is specifically identified by analogy with physical entities, and a unique non-dimensional number is proposed to evaluate the relative dominance of viscous to elastic effect. Through the simulation of two-dimensional Couette flow, the velocity profile and ar- rangement of particles are examined for various ratios of viscous to elastic effect. The effective viscosity of SPH particles de- creases as this non-dimensional number increases, while the increase of particle number significantly reduces the effective viscos- ity only at lower ratio of viscous to elastic effect. The disparity among nominal viscous dissipation, total dissipation, and theoreti- cal dissipation further confirms the presence of unphysical dissipation resulting from the elastic effect. In summary, due to the constraints from the Mach number and the ratio of viscous to elastic effect, there exists a critical Reynolds number below which the Newtonian behavior could be approximately obtained through suitable choice of model parameters.