Geometrically-Exact Extension of Theodorsen’s Frequency Response Model
Geometrically-Exact Extension of Theodorsen’s Frequency Response Model
复制标题
Theodorsen 频率响应模型的几何精确扩展
DOI：
--
复制
发表时间：
2015
期刊：
影响因子：
--
通讯作者：
M. Hajj
中科院分区：
文献类型：
--
作者：
H. Taha;Zhimiao Yan;M. Hajj
重新审视了 Theodorsen 的经典非定常理论，放宽了一些主要假设，例如 (1) 平坦尾流、(2) 小攻角、(3) 对平均流分量的小扰动以及 (4) 时不变自由流。为经历大幅度机动的翼型开发了半解析、几何精确、非定常势流模型。介绍了所开发模型的数值实现。所开发模型的非稳态预测根据实验和计算结果进行了验证。然后，确定不同攻角下流动动力学的频率响应。虽然在小攻角下与 Theodorsen 函数表现出良好的一致性，但在大攻角下获得的频率响应与 Theodorsen 函数之间观察到相当大的定性和定量差异。
The classical unsteady theory of Theodorsen is revisited relaxing some of the major assumptions such as (1) flat wake, (2) small angle of attack, (3) small disturbances to the mean flow components, and (4) time-invariant free-stream. A semi-analytical, geometricallyexact, unsteady potential flow model is developed for airfoils undergoing large amplitude maneuvers. The numerical implementation of the developed model is presented. The unsteady predictions of the developed model are validated against experimental and computational results. Then, the frequency response of the flow dynamics is determined at different angles of attack. While good agreement is shown with Theodorsen’s function at small angle of attack, considerable qualitative and quantitative discrepancies between the obtained frequency response at large angles of attack and Theodorsen’s function are observed.