脉冲风洞短时测力信号的延拓与动态载荷辨识方法  

Extension of balance signals in impulse tunnels and dynamic loads identification

作　　者：武龙[1] 王锋[1] 丁智坚[1] 陈圣兵[1] WU Long;WANG Feng;DING Zhijian;CHEN Shengbing(Science and Technology on Scramjet Laboratory,China Aerodynamic Research and Development Center,Mianyang 621000,China)

机构地区：[1]中国空气动力研究与发展中心,高超声速冲压发动机技术重点实验室,四川绵阳621000

出　　处：《振动与冲击》2020年第10期114-120,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(11372339);中国空气动力研究与发展中心风雷青年创新基金(FLYIF2016-26)。

摘　　要：研究了一种可快速辨识脉冲风洞中试验模型所受动态载荷的方法。给出了载荷、系统单位脉冲响应函数、天平输出三者的时域离散化模型,指出后者是前两者线性卷积的截断;将天平短时振荡输出延拓为完整的线性卷积结果,对前两者补零延拓,将上述模型转化为圆周卷积形式,进而通过离散傅里叶变换得到三者的频域离散化模型,求解频域模型得到载荷。通过单自由度系统简单载荷、多自由度系统复杂载荷两个数值模拟算例验证了该方法仅需对测量信号低通滤波即可准确辨识出载荷;经风洞试验,验证了方法的准确性和实用性。A fast identification method for dynamic loads in the impulse tunnel was presented. A time domain discretization model of loads, UIRFs(unite impulse response functions) and balance signals was proposed. To get a circular convolution form, balance signals were extended to linear convolution form while loads and UIRFs were zero padded. Then a frequency domain discretization model was obtained from the convolutional one by the discrete Fourier transform and dynamic loads were identified by solving it. A single-freedom-system-simple-load numerical simulation and a multi-freedom-system-complicated-load one were proposed to illustrate that the method was accurate as long as the measurement was low-pass filtered. Wind tunnel experiments validated the accuracy and practicability of the proposed method.

关 键 词：脉冲风洞 载荷辨识 圆周卷积 信号延拓 正则化方法 

分 类 号：V231[航空宇航科学与技术—航空宇航推进理论与工程] O329[理学—一般力学与力学基础]