风力机翼型S809绕流流动特性的POD和DMD对比分析OA北大核心CSTPCD
Comparative analyses of unseady flow fields around wind turbine airfoil S809 using POD and DMD
失速时的流动分离现象对风力机叶片的气动性能有重要影响,S809 作为典型水平轴风力机翼型,在临界失速攻角下气动性能会大幅降低.基于流动特征提取的非定常流场降阶模型(reduced-order model,ROM)是进一步深入了解非定常流动的重要手段.本文通过计算流体力学方法得到轻、深失速攻角下翼型的流动特征,对时变速度场进行本征正交分解(proper orthogonal decomposition,POD)和动态模态分解(dynamic mode decomposition,DMD)分析,得到轻、深失速下翼型的非定常流场信息(能量占比、模态频率等).通过两种方法的对比,结果表明,POD和DMD方法能够准确捕捉流动过程中的非定常结构和升力主频相同的典型模态,但是POD方法由于基于能量特征,在捕捉模态时会忽略与升力主频相近但能量较小的流动结构,而基于频率特征的DMD方法能够准确获得场的演化信息(增长率、频率等).本文研究有利于针对主频结构发展相应的流动控制方法,从而改善翼型流场情况,提高气动性能.
The flow separation remarkbaly undermines wind turbines'aerodynamic performance thus requires.In order to develop flow control strategies,fundelmental research on the unsteady flow separation is abosutely necessary,and the Reduced-Order Model(ROM)methods offers a tool.In this paper,the unsteady flow fields around S809,a typical horizontal axis wind turbine airfoil,at deep and shallow stall angles of attack are obtained numerically and further analyzed by proper orthogonal decomposition(POD)and dynamic mode decomposition(DMD).Results show that POD and DMD can accurately capture the unsteady flow structures and dominant modes,but the former,based on magnitude of energy,ignores the flow structure with similar lift main frequency but less energy.DMD can accurately capture the flow field evolution(rate of increase,frequency,etc.)and develop targeted flow control strategies for the dominant frequency structure,offering the airfoil flow field conditions and aerodynamic performance.
李凯迪;孙晓晶
上海理工大学能源与动力工程学院,上海 200093||上海市动力工程多相流动与传热重点实验室,上海 200093
能源与动力
风力机翼型绕流计算流体力学降阶模型本征正交分解动态模态分解
wind turbine airfoil flowunsteady flow separationreduced-order modelproper orthogonal decomposition(POD)dynamic mode decomposition(DMD)
《空气动力学学报》 2024 (003)
55-68 / 14
国家自然科学基金面上项目(52176194)
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