Adaptation of Aeroelastic Reduced-Order Models and Application to an F-16 Configuration
Adaptation of Aeroelastic Reduced-Order Models and Application to an F-16 Configuration
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DOI：
10.2514/1.24512
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发表时间：
2007-06
期刊：
影响因子：
2.5
通讯作者：
Thuan Lieu;C. Farhat
中科院分区：
文献类型：
--
作者：
Thuan Lieu;C. Farhat
适当的正交分解方法已被证明可以产生精确的降阶模型，用于固定飞行条件下完整飞机构型的气动弹性分析。然而，马赫数或攻角的变化往往需要重构降阶模型以保持精度，这破坏了所追求的计算效率。降阶模型自适应的直接方法--如全局正交分解法和正交分解基矢量的直接插值--在过去曾尝试过，结果表明，在跨音速飞行状态下，这些方法会导致正交分解基不准确。另外，本文描述了一种新的降阶模型自适应方案，并对自由飞行马赫数和攻角的变化进行了评估。该方案在两个正交分解子空间之间插值子空间角，然后基于插值子空间角进行正交变换，生成新的正交分解基。所得的计算方法适用于一个完整的F-16配置在各种气流。预测的气动弹性频率和阻尼系数进行了比较，从全阶非线性气动弹性模拟和飞行试验数据得到的同行。观察到良好的相关性，包括在跨音速制度。所获得的计算结果揭示了一个显着的潜力，适应降阶模型计算技术的准确，近实时，气动弹性预测。
The proper orthogonal decomposition method has been shown to produce accurate reduced-order models for the aeroelastic analysis of complete aircraft configurations at fixed flight conditions. However, changes in the Mach number or angle of attack often necessitate the reconstruction of the reduced-order model to maintain accuracy, which destroys the sought-after computational efficiency. Straightforward approaches for reduced-order model adaptation-such as the global proper orthogonal decomposition method and the direct interpolation of the proper orthogonal decomposition basis vectors-that have been attempted in the past have been shown to lead to inaccurate proper orthogonal decomposition bases in the transonic flight regime. Alternatively, a new reduced-order model adaptation scheme is described in this paper and evaluated for changes in the freestream Mach number and angle of attack. This scheme interpolates the subspace angles between two proper orthogonal decomposition subspaces, then generates a new proper orthogonal decomposition basis through an orthogonal transformation based on the interpolated subspace angles. The resulting computational methodology is applied to a complete F-16 configuration in various airstreams. The predicted aeroelastic frequencies and damping coefficients are compared with counterparts obtained from full-order nonlinear aeroelastic simulations and flight test data. Good correlations are observed, including in the transonic regime. The obtained computational results reveal a significant potential of the adapted reduced-order model computational technology for accurate, near-real-time, aeroelastic predictions.