高雷诺数不可压湍流中柔性结构非线性流固耦合振动机理研究

The mechanism of the vortex dynamics, vortices-wing interference , and nonlinear fluid-structure coupled vibration of the flexible structures in the unsteady turbulence flow are the premise and foundation of the design of high performance intelligent/bionic aircrafts. In this proposal the geometrically nonlinear large deformation fluid-structure coupled dynamic behaviors of flexible structures in high Reynolds number incompressible turbulence flow will be investigated by numerical method and experimental research. We will develope a new coupled high accurate nonlinear fluid-structure interference numerical simulation method based on immersed boundary method (IB)-lattice lattice Boltzmann method( LBM)-finite element method(FEM). And then the large scale parallel computing method for the developed IB-LBM-FEM solver in graphic process unit (GPU)/CPU heterogeneous cluster environment will be proposed. The integrated optical measurement method for the flexible structural deformation and movement, the structrual vibration, and the unsteady flow vortex structures will also be developed to verify the proposed new numerical simulation solver.The unsteady turbulent vortex structure evolutions and the large deformation coupled vibration mechanism in turbulence flows will be revealed in order to provide a theory and method supports for the high performance flexible/bionic aircraft aerodynamic/ structural design. The innovations of this proposal include the GPU-accelerated IB-LBM-FEM coupled high accurate numerical simulation method for flexible structures and the turbulence- structure coupled vibration mechanism of the flexible wings in high Reynolds number incompressible turbulence flow.

对非定常流场中柔性结构变形运动伴随的涡动力学、涡-翼干扰、流固耦合振动机理的深入认识是设计高性能可变智能/仿生飞行器的前提和基础。本项目针对柔性结构在高雷诺数不可压缩湍流中大变形流固耦合动力学行为，采用数值模拟与风洞试验验证相结合的技术途径，发展基于IB-LBM-FEM的柔性结构-湍流非线性流固耦合振动高精度数值模拟方法，研究GPU/CPU异构集群环境下IB-LBM-FEM流固耦合大规模并行数值模拟技术，建立柔性结构变形运动、结构振动和非定常流场一体化光学测试方法，揭示柔性结构大变形运动情况下流固耦合振动机理以及伴随的非定常湍流涡系结构演化过程，为高性能柔性/仿生飞行器气动/结构设计提供方法和理论支撑。本项目创新点包括基于GPU加速的高雷诺数流动IB-LBM-FEM流固耦合并行数值模拟方法，以及高雷诺数不可压湍流中柔性结构非线性流固耦合振动机理。

本研究针对柔性结构在非定常不可压流动中大变形流固耦合的动力学行为，采用数值模拟和风洞实验相结合的手段，揭示了柔性结构大变形非定常流动下流固耦合的振动机理。建立了大规模可并行IB-LB-FEM（Immersed Boundary-Lattice Boltzmann-Finite Element Method）数值模拟方法，提出了柔性结构变形运动、结构振动和非定常流场一体化风洞实验测试方法。利用发展的高性能数值模拟方法，对不同参数下仿生拍动翼的气动特性和推进性能进行了数值模拟研究，探究了影响拍动翼非定常流动的因素及其变化规律，给出了非定常流动详细的流场信息和涡系结构。对高雷诺数流场中柔性结构大变形流固耦合振动机理进行了数值模拟研究，提出了利用柔性结构进行机翼边界层流动控制的方法，提升了机翼整体的气动性能。同时建立了结构参数变化下湍流气动弹性降阶模型建模方法。采用风洞实验方法，研究了不同柔度薄板翼的流固耦合振动情况，并对其气动噪声进行了测试。所提出的数值模拟方法精度高、并行性能强，实验方案可行性好，可操作性强，给出的非定常流动机理以及流固耦合振动机理为高性能柔性仿生结构设计提供了有力的理论支撑。