仿生非光滑表面减阻性能研究

Study on Drag Reduction Performance of Bionic Non Smooth Surface

在天然气的长距离管道输送过程中,减少运输中产生的沿程阻力非常重要。为了减少管道输送中的沿程阻力,提高管道的运输效率,通过学习自然环境下昆虫等生物进化得到的自然筛选,并将仿生学应用到减阻方面变得尤为重要。研究非光滑壁面管道摩擦阻力的特性,建立仿生凹坑理论模型,并采用RNG k-ε模型对流动进行分析,同时结合仿生学基础和流体力学知识,利用Catia进行三维建模,利用Ansys等软件进行数值模拟,通过研究、对比凹坑型、凸起型以及不同深度情况下,分析流体在管道内的流动情况,并通过对比管道内湍流强度和压力,可以进一步得出不同模型的减阻效率。研究发现,相较于凸起和平面结构,凹坑结构的减阻效率更高,凹坑结构内部产生堆成结构涡流是凹坑结构可以减阻的重要原因。

In the process of long-distance pipeline transportation of natural gas,it is very important to reduce the frictional resistance generated during transportation.In order to reduce the resistance along the pipeline transportation and increase the transportation efficiency of the pipeline,it is particularly important to learn the natural screening obtained from the evolution ofinsects and other organisms in the natural environment and apply bionics to drag reduction.In this paper,the characteristics of friction resistance of non smooth wall pipes was studied,a bionic crater theoretical model was established with RNG k-e.The flow was analyzed by the model.At the same time,combining the bionics foundation and fluid mechanics knowledge,Catia was used for three-dimensional modeling,and Ansys and other software were used for numerical simulation.By studying and comparing the flow of fluid in the pipe under the conditions of concave,convex and different depths,the drag reduction efficiency of different models was further obtained by comparing the turbulence intensity and pressure in the pipe.It was found that the drag reduction efficiency of the pit structure was higher than that of the convex and plane structures,and the stacking structure vortex in the pit structure wasan important reason for the drag reduction of the pit structure.