Design and characteristics on wing of extreme big aspect ratio 大展弦比夹芯翼大攻角颤振分析
Flutter analysis on aircraft for the condition of unsymmetrical stores 全机非对称外挂状态颤振分析
So , the correct prediction of the blade flutter is very important in the design and modification of the turbomachine 因此,建立叶片颤振分析预测系统对叶轮机设计和改型是十分必要的。
With this kind of element , panel flutter analysis can be performed not only for thin plates but for the middle - thickness laminates 由于min3单元计及了壁板的横向剪切效应,因此这种壁板颤振分析方法不仅可以针对薄板,而且可以针对具有中等厚度的复合材料层合板。
The newmark method is used to solve the panel flutter equations in time domain . the linear flutter boundaries are determined and the effect of temperature on flutter boundaries is analyzed 编制了壁板颤振分析的有限元程序,采用newmark方法在时域中求解了壁板的线性颤振方程,确定了壁板的颤振边界,分析了温度对壁板颤振边界的影响。
In the engineering background of a suspension bridge tender project , taking the bridge and the airflow as a whole system , the effectiveness of the surface in the flutter stability of the system is studied by a multi - mode flutter analysis approach 以某悬索桥设计方案为工程背景,把桥梁与气流作为一系统,应用多模态颤振分析方法,研究了在主梁下风侧设置翼板这种控制措施对改善该系统颤振稳定性的效果。
Second , the structural dynamic equations for blades are introduced in this paper . through numerically solving the aerodynamics - structure coupled equations , a 2 - d unsteady viscous flow in a single cascade is investigated under flow - structure coupled conditions , and a preliminary analysis of the cascade flutter is prosecuted 其次,本文引入叶片结构动力学方程,通过数值求解气动结构耦合方程体系,研究了气固耦合条件下叶栅内的二维非定常粘性流动,并初步进行了叶栅的颤振分析。
As to the current problems existing in the identification for these flutter derivatives , the dissertation tries to trace the development in the identification for the past unsteady aerodynamic forces of long - span bridges . it also investigates the method for flutter and buffeting analysis and the flutter derivatives . based on the present methods used in obtaining the unsteady aerodynamic forces and flutter derivatives , and co - funded by a natural scientific fund from the nation and a key project fund from the railway ministry , the current research has attempted to develop a device which can be employed in the wind tunnel to test flutter derivative through a forced vibration method 鉴于目前桥梁断面颤振导数识别的水平和存在的问题,本文通过对大跨度桥梁非定常气动力、颤振分析方法及颤振导数识别方法的回顾和评述,基于现有的非定常气动力和颤振导数的测试方法,在国家自然科学基金与铁道部重点学科基金的联合资助下,研究开发了一套在风洞中采用强迫振动法测试颤振导数的装置。