Multivariate Splines-Based Asymmetric Aerodynamic Modeling of Morphing Aircraft

基于多元样条函数的变体飞机非对称气动力建模

¹ School Aeronautics, Northwestern Polytechnical University, Xi'an 710072, China
² Experimental Aircraft Design and Flight Testing Lab of Shaanxi, Xi'an 710072, China

Received: 4 May 2017

Abstract

The aerodynamic parameters of morphing aircraft can vary significantly in the morphing process; the aerodynamic data model is complex and high-order nonlinear. This paper presents a new method of aerodynamic modeling of morphing aircraft by using multivariate splines. Firstly, the aerodynamic coefficient model of morphing aircraft based on the multivariate splines model structure is presented. This model can describe symmetric and asymmetric aerodynamic forces. Then, the multivariate simple splines estimation process is introduced in detail and the concrete formulation is deduced. Finally, the final model structure is determined by error analysis, and the aerodynamic parameter polynomial model in the global coordinate system is obtained by coordinate transformation. The results show that this method can accurately describe the aerodynamic model of morphing aircraft during arbitrary symmetric and asymmetric morphing process without predicting the specific model structure of the aerodynamic parameters related to varying process.

摘要

针对变体飞机在变形过程中气动参数变化剧烈，气动数据模型复杂、高阶且含有强非线性这些特性，提出了一种采用多元样条函数对变体飞机气动参数进行建模和估计的方法，解决了变体飞机非对称变形过程的气动力建模问题。首先给出了基于多元样条函数模型结构的变体飞机气动系数模型，该模型能够描述任意对称和非对称的气动力情况；然后详细介绍了多元单形样条函数参数估计流程并推导了具体公式；最后通过误差分析确定了最终模型结构，并通过坐标转换得到总体坐标系中的气动参数多项式模型。结果表明，该方法无需预知变形相关的气动参数具体模型结构，能够得到准确描述任意对称和非对称变形状态下的变体飞机气动力模型。