改变列车外形降低隧道内作用在高速列车上的非稳态气动力

随着日本新干线高速列车最高速度的增加,隧道内由流体诱发的车体振动已成为研讨的课题之一。本文介绍了改变列车外形降低作用在列车上的非稳态气动力的研究结果。

具有操纵面间隙非线性二维翼段的气动弹性分析

基于Theodorsen理论和Wagner函数,提出了不可压缩流作用下三自由度二维翼段任意运动非定常气动力表达式。对操纵面自由度具有的间隙非线性,建立了二维翼段气动弹性系统无量纲分段线性运动方程。数值仿真预示了系统极限环振动的相轨迹、无量纲振动幅值和频率,表明操纵面铰链处存在的间隙非线性将导致整个系统的极限环振动;随着来流速度的增加,系统极限环振动的幅值和频率都存在跳跃现象。

Description and Estimation of Unsteady Aerodynamic Forces for Application to Elastic Aircraft

In this paper, Duhamel's integral of the indicial function is used to describe unsteady aerodynamic forces. An identification method to estimate the aerodynamic forces is proposed for elastic aircraft by the maximum likelihood algorithm with estimated sensi tivities. A numerical example is given and the calculated results show the effectiveness of this method.