基于流固双向强耦合的车辆风激振特性对侧风行驶稳定性的影响研究

The influence of the vehicle body vibration caused by the high-speed ambient wind on the vehicle handling stability is studied in this topic based on the transient test technology of automobile crosswind experimental platform, the CFD transient numerical simulation technology considering the fluid-solid coupling effect and the transient structural mechanics simulation research method. By conducting the fluid-solid coupling test on the vehicle model with the wind tunnel test combined with road test technology, the law of instantaneous changes of aerodynamic load and vibration characteristics of the vehicle model under different wind speed conditions will be obtained, which provided the experimental basis for the numerical simulation. Considering the mutual coupling effect of transient flow field and vehicle body vibration, the vibration characteristics of vehicle body under different crosswind conditions and different vehicle speed conditions are studied. Considering the mutual coupling of transient flow field and vehicle body vibration, the transient topological structure of the separated flow and vortex will be obtained by studying the vibration characteristics of vehicle body under different crosswind conditions and different vehicle speed conditions, the transient characteristics of separated flow and vortex of the flow field under unsteady wind condition. The wind excitation characteristics of the vehicle body cover are studied, and the method of suppressing the wind-induced vibration hazard is proposed by analyzing the transient characteristics of the flow field around the vehicle and the transient aerodynamic loads. The research results of this topic will provide references for the development of pneumatic modeling of domestic automobiles, the operation of intelligent vehicle systems and intelligent driving. They will also improve the driving stability of vehicles and ensure the safety and ride comfort of vehicles running at high speed.

基于车辆侧风实验平台的瞬态测试技术、考虑流固耦合效应的CFD瞬态数值模拟技术以及瞬态结构力学仿真研究方法，研究高速行驶时环境风引起的车身振动现象对车辆行驶稳定性的影响。通过风洞试验联合道路试验技术对试验模型进行流固耦合试验，获取试验车模型在不同风速条件下的气动载荷、振动特性等参数瞬时变化规律，为数值仿真提供实验依据；考虑瞬态流场与车身振动相互耦合作用，研究不同侧风、不同车速工况条件下车身振动特性，车辆流场在非稳定风下分离流与旋涡的瞬态特性，获得车辆分离流与旋涡运动的瞬态拓扑结构；研究车身覆盖件的风激振特性，通过分析汽车周围流场瞬态特性和瞬态气动载荷的变化规律，提出抑制或改善风激振危害的方法。本课题的研究成果为国产汽车气动造型开发、智能车辆系统的操纵以及智能驾驶提供参考依据，提高车辆行驶稳定性，保障车辆高速行驶的安全性和舒适性。

车辆侧风稳定性是汽车轻量化和高速化发展中的重要研究方向。本课题基于车辆侧风实验平台的瞬态测试技术、考虑流固耦合效应的CFD瞬态数值模拟技术以及瞬态结构力学仿真研究方法，开展了整车高速行驶工况下环境风对车辆行驶稳定性的影响与机理研究。首先开发了整车流固耦合数值仿真方法，并建立流固耦合风洞试验台用以验证仿真方法；其次研究不同侧风、不同车速工况条件下车身振动特性，车辆流场在非稳定风下分离流与旋涡的瞬态特性，获得车辆分离流与旋涡运动的瞬态拓扑结构；然后通过分析汽车周围流场瞬态特性和车辆瞬态动力学响应，提出车辆侧风稳定性评价方法；最后开展车辆侧风稳定性的控制研究，建立Kriging近似模型对车辆参数进行优化设计，同时基于主动悬架的ECS技术，设计车身姿态模糊控制系统和悬架垂向力控制算法，充分发挥主动悬架的控制作用，达到改善车辆车辆侧风稳定性的目的。本课题的研究成果为国产汽车气动造型开发、智能车辆系统的操纵以及智能驾驶提供参考依据，提高车辆行驶稳定性，保障车辆高速行驶的安全性和舒适性。