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基于几何非线性的浅拱理论及空气动力学理论,建立了局部弹性翼型的气动弹性模型,并针对该模型建立了在ALE坐标下局部弹性翼型与非定常流场的耦合算法;对振动NACA0012翼型的非定常气动力进行了计算,结果与文献数据吻合良好,验证了算法的准确性;对雷诺数为2×105时弹性翼面自激振动对翼型的增升减阻效应进行了数值分析.研究结果表明,同刚性翼型的气动特性相比,翼型的局部弹性自激振动使翼型的气动特性得到了明显改善:其失速角度从原来的13°推迟到了16°;在大攻角下,翼型的升阻比提高了80%以上.频谱分析发现:在攻角为8°和11°时,翼面振动与流场的耦合出现同步现象;在攻角为16°时,翼型的局部自激振动使剪切层内形成一系列小尺度涡,同时削减了大涡的尺寸,这使得升、阻力的波动幅度减小,在一定程度上改善了翼型的气动性能.文中建立的气弹模型具有明显的减阻增升效果,可望应用于翼型的优化设计.
Based on the geometrical nonlinear shallow arch theory and aerodynamics theory, aeroelastic model of a local elastic airfoil is established, and the coupling algorithm of local elastic airfoil and unsteady flow field is established for the model. The unsteady aerodynamic force of NACA0012 airfoil is calculated and the result is in good agreement with the literature data to verify the accuracy of the algorithm. For the airfoil with self-excited vibration of 2 × 105 Reynolds number, drag reduction effect The numerical results show that compared with the aerodynamic characteristics of the rigid aerofoil, the local elastic self-excited vibration of the aerofoils significantly improves the aerodynamic characteristics of the aerofoil: the stalling angle is delayed from 13 ° to 16 °; At large angles of attack, the lift-drag ratio of the airfoil is increased by more than 80% .Analysis of the frequency spectrum shows that the coupling of the airfoil vibration and the flow field is synchronous at the angles of attack of 8 ° and 11 °, °, the local self-excited vibration of the airfoil forms a series of small-scale vortices in the shear layer and reduces the size of large vortices, which reduces the fluctuations of the ascending and descending resistances and improves the airfoil’s Aerodynamic performance. Aeroelastic model established in this article Significant drag lift effect, expected to be used to optimize the design of the airfoil.