【作者】 王俭；

【导师】 杨波；

【作者基本信息】 上海交通大学 ， 动力机械与工程， 2010， 硕士

【摘要】 由于叶轮的旋转,叶轮机内部流动是非定常的。在设计和计算中,我们就需要考虑非定常的特性。时序效应,作为一种利用非定常特性以提高叶轮机械气动性能的方法,受到研究者关注。所谓叶轮机械时序效应,即指改变前后级同名叶片周向相对位置,会对整个机械性能产生影响。本文采用CFD方法来研究时序效应的产生机理,提出相关公式对轴流叶轮机械前后级进行时序定位。论文采用Numeca软件对NASA实验用1.5级(静/转/静)轴流压气机进行了二维以及三维非定常数值模拟,同时引入汉诺威大学的1.5级实验透平二维计算以及对应的全通道环列计算作为比较,根据计算的结果,分析出时序效应产生的机理主要在于两方面:一.动叶的非定常气动力受到前排静叶尾迹扰动以及后排叶栅中周期性变化的压力场所产生的势扰动的同时影响,时序位置的改变,会使两种扰动产生有利或不利的迭加,从而减小或增大了动叶表面的非定常气动力。二.第一级静叶尾迹在最佳时序位置时,与第二级静叶附面层发生了有利的干扰,从而减小了流动损失,使得效率有所提高。在机理研究的基础上,针对该1.5级轴流透平及压缩机算例,我们对时序定位的方法在二维以及三维上均进行了探讨,以期达到最佳效率及气动性能。二维定位上,提出了简化的公式,并利用数值模拟的结果进行了验证,结果表明,该时序定位方法具有一定的参考价值。三维时序定位本文尝试改变第二级静叶前缘线的形状,以期达到最大化时序效应。更多还原

【Abstract】 The method of turbo machinery’s design is almost based on steady hypothesis. But actually, because of the rotation of rotor, the flow in turbo machine is unsteadying. So we should consider this fact in design and calculation. Clocking effect, as a method which consider the unsteady fact to improve the performance of turbo machine is concentrated by more and more people.Clocking effect means that, the change of the blade’s circumferential position makes influents of the turbo machinery’s performance .In this thesis, CFD tool is used to investigate the mechanism of clocking effect, and a simple way is suggested about conforming stator’s relative circumferential position. Numeca software is used to make a 2D and a 3D numerical simulation of an 1.5 row axial compressor,and a 1.5 row turbo’s 2D and all channels quia-3D is also used. According to the results , it gets the mechanism consists in following two points : firstly, the rotor unsteady aerodynamic force is influenced by both the wake of the first stator and the downstream potential effect , in the best clocking location, these two effects have good combine which can decrease rotor unsteady aerodynamic force; secondly , in the best clocking location , the first stator’s wake gives a good influence in the second stator’s boundary layer which makes the lose decreased. After getting the mechanism, A simple way is suggested about conforming stator’s relative circumferential position. The purpose of this suggestion is to make sure that the turbine or the compressor can reach the best performance. And then, Numeca software is used to make a 2D numerical simulation to confirm this method. Results show that the method has a certain value in the structure design of turbo machine. In 3D condition, we try to change the performance of second stator’s leading edge to make the best use of clocking effect.更多还原