非均匀高分子聚合物用于水中航行器外部流动减阻特性研究

项目名称： 非均匀高分子聚合物用于水中航行器外部流动减阻特性研究

项目编号： No.11502087

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 数理科学和化学

项目作者： 熊永亮

作者单位： 华中科技大学

项目金额： 25万元

中文摘要： 水中加入微量的水溶性高分子聚合物可大幅降低湍流引起的摩擦阻力。对于诸如船舶与水中兵器等涉及外部流动的阻力，该技术具有巨大的减阻潜力。然而对于外部流动而言，物体表面的高分子聚合物并非均匀分布。本项目拟采用数值模拟的方法，研究水中物体外部的非均质聚合物作用下的粘弹性流场。鉴于高分子聚合物可大幅更改湍流结构，本课题一方面需考虑流动对聚合物的湍流扩散作用，另一方面需要考虑非均匀的聚合物对流动的更改；耦合两方面来探索非均质聚合物对物体表面摩擦阻力的影响。拟在前期工作基础上，考虑聚合物分子受对流与扩散作用，通过计算分析在聚合物浓度梯度达到统计平衡态时的减阻能力以及小尺度脉动规律，并进一步研究有聚合物扩散的非定常零压梯度边界层的阻力与聚合物浓度扩散行为。此外将通过实验对数值计算进行验证，并通过实验方法研究含聚合物自抛光防污涂料对阻力及边界层流动的影响，为外部流动的聚合物减阻提供可行的实施方案与理论指导。

中文关键词： 减阻；粘弹性流体；数值模拟；湍流结构；扩散

英文摘要： A small amount of polymer additives with high molecular weight may dramatically reduce the friction drag in turbulent flow. This technology was applied to reduce the fuel consumption for transporting crude oil successfully. Furthermore, the technology has the potential to reduce the drag for the external flow such as the drag of ship and the drag of underwater vehicle. However, the polymer solution for those external flows isn’t homogeneous as its counterpart of inner flows. In this project, we would like to study the inhomogeneous viscoelastic flow outside of the underwater object by numerical simulation. Considering the turbulent flow can be modified considerably, on one hand the dispersion of polymer molecular should be taken into account in turbulent flows; on the other hand, it is necessary to study the polymer’s influence on the flow modification. In this project, we would like to study the friction drag of an object under the influence of inhomogeneous polymer solutions couple with these two factors together. Based on our previous in-house computational fluid dynamics code which can simulate a flow with homogeneous polymer additives, we will model the dispersion of polymer molecular in turbulent flow to study the interaction between the Newtonian flow and high molecular weight polymer. The maximum drag reduction and small scale fluctuation are going to be focused in this project while the inhomogeneous polymer solution stay in a state of statistical equilibrium. Furthermore, the concentration of polymer additives and the friction drag on a zero-pressure-gradient boundary layer with polymer injection will be studied in this project. The numerical results will be adequately validated by experimental results; the influence of polymer on drag and flows in the boundary layer will be studied by experiments by means of Anti-Fouling marine paint contains polymer. The current investigation can be served as an effective theoretical support and an executable method for the drag reduction with an external flow such as a ship as well as an underwater vehicle with polymer additives on the surface.

英文关键词： drag reduction;viscoelastic fluid;numerical smulation;turbulent structure;dispersion