基于浸没边界法的壁面凸起对仿生鱼游动影响的研究  

Research on the influence of wall protrusions on biomimetic fish swimming based on the immersed boundary method

作　　者：张仲毅 户大勇 张军[1] 焦艳梅 ZHANG Zhongyi;HU Dayong;ZHANG Jun;JIAO Yanmei(College of Aeronautics,Key Laboratory of Unsteady Aerodynamics and Flow Control,Ministry of Industry and Information Technology,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China;School of Physical and Mathematical Sciences,Nanjing Tech University,Nanjing 211816,China)

机构地区：[1]南京航空航天大学航空学院非定常空气动力学与流动控制工信部重点实验室,江苏南京210016 [2]南京工业大学数理科学学院,江苏南京211816

出　　处：《海洋工程》2024年第5期97-105,共9页The Ocean Engineering

基　　金：水动力学全国重点实验室基金项目(61422030302);国家自然科学基金青年科学基金项目(52106246);江苏省基础研究计划(自然科学基金)青年基金项目(BK20200687)。

摘　　要：流体流经壁面凸起后在壁面凸起的后方产生周期性脱落的尾涡,尾涡内流场复杂。当尾涡继续流动流经游动中的仿生鱼时,仿生鱼的水动力系数也随之发生剧烈变化。基于多重直接力浸没边界法,结合狄拉克函数,通过求解不可压缩Navier-Stokes(N-S)无量纲方程,对低雷诺数情况下的仿生鱼游动过程进行无量纲化数值模拟研究。为了验证算法和自主开发程序的准确性,对圆柱绕流和NACA0012外形鱼体游动流场进行了验证算例计算,计算结果与文献结果吻合较好,验证了算法和程序的有效性。在此基础上,研究固壁半圆形凸起对仿生鱼游动水动力系数的影响,计算结果表明:当仿生鱼距壁面较近时(d=0.25L),仿生鱼受到远离壁面方向的侧向力和顺时针方向力矩;当仿生鱼距壁面较远时(d=1.25L),仿生鱼受到指向壁面的侧向力和逆时针方向力矩。总体而言,壁面凸起使得仿生鱼更容易在与壁面有一定距离的高度区间内游动,壁面凸起对仿生鱼游动起到了一定减阻作用。When fluid flows past wall protrusions,periodic shedding of vortices occurs behind the protrusions,resulting in a complex flow field within the vortices.As these vortices continue to flow past a swimming biomimetic fish,the hydrodynamic coefficients of the fish undergo significant changes.Based on the multiple direct forcing immersed boundary method,combined with the Dirac function,the non-dimensional Navier-Stokes(N-S)equations for incompressible flow are solved to numerically simulate the swimming process of the biomimetic fish at low Reynolds numbers.To verify the accuracy of the algorithm and the self-developed program,validation calculations were performed for the flow around a cylinder and the swimming flow field of a NACA0012 shaped fish body.The calculated results agree well with the literature,confirming the effectiveness of the algorithm and the program.On this basis,the study investigates the influence of semi-circular wall protrusions on the hydrodynamic coefficients of the biomimetic fish swimming.The results show that when the biomimetic fish is close to the wall(d=0.25L),it experiences a lateral force away from the wall and a clockwise moment.When the biomimetic fish is farther from the wall(d=1.25L),it experiences a lateral force towards the wall and a counterclockwise moment.Overall,the wall protrusions make it easier for the biomimetic fish to swim within a certain height range from the wall,the wall protrusions also provide some drag reduction for the biomimetic fish swimming.

关 键 词：仿生鱼游动 近壁效应 浸没边界法 数值模拟 

分 类 号：P754[天文地球—海洋科学] O351.2[理学—流体力学]