强迫振动和极限环振动时域响应的高效预测方法研究  

Efficient prediction for time domain responses of forced oscillations and limit cycle oscillations

作　　者：刘艳[1] 白俊强[1] 华俊 刘南[1] 

机构地区：[1]西北工业大学航空学院,西安710072 [2]中国航空研究院,北京100012

出　　处：《振动与冲击》2016年第13期140-147,共8页Journal of Vibration and Shock

基　　金：国家"973"计划(2014CB744804)

摘　　要：建立一种基于改进Kriging的KSBRF(Kriging-Surrogate-Based Recurrence Framework)降阶模型(ReducedOrder Model,ROM),用于高效地预测非线性非定常气动力及力矩、极限环振动(Limit Cycle Oscillations,LCO)等。首先基于Kriging代理模型建立非线性系统输入-输出关系的循环预测框架。然后对翼型做沉浮/俯仰组合运动时的非线性非定常气动力进行辨识。结果表明:在固定来流马赫数情况下,KSBRF预测结果与CFD计算结果吻合良好,阻力系数及俯仰力矩系数等的平均预测误差均在2.0%以内;在变来流马赫数情况下,升力系数和俯仰力矩系数的平均预测误差在2.5%以内,而阻力系数的预测误差则稍大,但也不超过7.0%。通过研究不同m,n取值对模型精度的影响,得出考虑历史效应有利于提高当前时间步的模型预测精度。除此之外,还对NACA64A010翼型的LCO振动形态进行预测,预测结果与CFD计算结果吻合良好,误差均保证均小于5.17%,节省近三分之二的计算时长。A nonlinear reduced-order model（ ROM） using Kriging surrogate-based recurrence framework（ KSBRF） was built. Because Kriging interpolation has the ability of estimating nonlinear input-output relationship,nonlinear aerodynamic forces and characteristics of LCO（ limit cycle oscillations） could be estimated with KSBRF ROM.Firstly,the relationship between input and output of a nonlinear system was built using KSBRF ROM. Then,the identification of nonlinear unsteady aerodynamic forces was conducted when an airfoil had pitch / plunge oscillations. It was shown that under the same free-stream＇s Mach number,the prediction results with KSBRF ROM agree well with those with CFD,the mean prediction errors of drag coefficient and pitch moment coefficient are within 2. 0%; considering a variable free-stream Mach number,the mean prediction errors of lift coefficient and pitch moment coefficient are within 2. 5%,the preceding error of drag coefficient is less than 7%; it is concluded that considering the history effect is helpful to improve the accuracy of ROM through studying the effects of different m, n values on the accuracy of ROM; the LCO characteristics of NACA64A010 airfoil are predicted with the nonlinear ROM,the prediction results with KSBRF ROM agree well with those with CFD,the errors are less than 5. 17%.

关 键 词：代理模型 降阶模型 KRIGING插值 非定常气动力 极限环振动 

分 类 号：V215.32[航空宇航科学与技术—航空宇航推进理论与工程] V211.3