瞬态非牛顿流体非定常流动问题的等几何分析

Isometric Analysis of Unsteady Flow of Tran-sient Non-Newtonian Fluids

非牛顿流体非定常流动问题是指流动过程中流体的物理性质随时间变化的复杂流动问题,为了改进传统分析方法在处理复杂流动问题上精度及效率不足的缺陷。本文从经典N-S方程入手,推导出了一种高效等几何求解方法,通过选择合适的等效流动参数,确定等价定常流动条件,将复杂非定常问题转化为一组等价的定常流动问题。最后以平板拖曳模型为例,得到了各时刻流体的速度分布,并与商业分析软件进行对比,通过不同的迭代步长的计算精度,来验证该方法的计算效率。该方法能帮助工程人员更好地理解流体的流动特性,为设计优化工艺过程和提高机器设备的效率提供重要的理论依据。

Non-newtonian fluid unsteady flow problem refers to the complex flow problem in which the physi-cal properties of the fluid change with time. In order to improve the defect of the traditional analy-sis method in dealing with the complex flow problem, the accuracy and efficiency are insufficient. Based on the classical N-S equation, an efficient isogeometric solution method is derived. By select-ing appropriate equivalent flow parameters and determining equivalent steady flow conditions, complex unsteady problems are transformed into a set of equivalent steady flow problems. Finally, the fluid velocity distribution at each moment is obtained by taking the flat plate towing model as an example, and compared with commercial analysis software, the computational efficiency of the proposed method is verified by calculating accuracy of different iteration steps. This method can help engineers better understand the flow characteristics of the fluid and provide important theo-retical basis for optimizing the design process and improving the efficiency of machinery and equipment.