带分流叶片叶轮的模型重建及其性能分析

发布时间：2018-03-18 21:30

本文选题：整体叶轮　切入点：分流叶片　出处：《南京航空航天大学》2012年硕士论文　论文类型：学位论文

【摘要】：叶轮机械作为主要部件广泛应用在航空航天航海、地面推进系统、能源动力、石油化工等行业。带分流叶片整体叶轮在工作状态下内部流动特性复杂，强度和振动问题是导致故障的主要原因。本文实现了一种带分流叶片整体叶轮的实体模型重建，分析了该重建叶轮的气动特性、强度和振动模态以及单向流固耦合场对强度和模态的影响。论文的主要工作内容和取得的成果如下： 1、利用Imageware及UG软件，采用基于特征提取的重建方法，实现了一种带分流叶片叶轮的实体模型重建，并给出了具体的重建方案。 2、利用ANSYS Workbench及自带的CFX软件分析了重建叶轮的气动特性，绘制了叶轮流量特性曲线。结果表明重建叶轮的流场分布均匀、从进口到出口处压力增加均匀，在设定转速及背压下叶轮压比高、效率高，叶轮设计优良。当叶轮转速较高时，叶轮尾缘处出现一定程度的回流和漩涡。 3、使用ANSYS Workbench软件分析了叶轮的强度及模态。分析给出了叶轮的最高安全转速，低周疲劳临界转速及临界转速。结果表明重构叶轮最大应力出现在叶轮下端面靠近中心孔的轮毂处，叶片上最大应力集中在叶片前缘靠近叶根处。叶片前缘靠近叶尖处振动时振幅最大，发生局部共振的可能性最大，在非定常气动力载荷以及其它激振力的长期作用下，叶片前缘处容易形成高周疲劳断裂。 4、运用ANSYS Workbench软件分析了叶轮在流固耦合场下的强度及模态。分析结果表明气动力对叶轮的强度有一定影响，气动力导致叶轮的应力增大，然而叶轮的变形有微小的减少；同时，流固耦合场对叶轮模态影响不大，可以忽略。
[Abstract]:Impeller machinery is widely used in aerospace navigation, ground propulsion system, energy power, petrochemical industry and so on. The strength and vibration problems are the main causes of the failure. In this paper, a solid model reconstruction of the integral impeller with shunt blade is realized, and the aerodynamic characteristics of the reconstructed impeller are analyzed. The influence of strength and vibration mode and unidirectional fluid-solid coupling field on strength and mode. 1. By using the software of Imageware and UG, a reconstruction method based on feature extraction is used to reconstruct the solid model of impeller with shunt blade, and the concrete reconstruction scheme is given. 2. The aerodynamic characteristics of the reconstructed impeller are analyzed by using ANSYS Workbench and CFX software. The flow characteristic curve of the reconstructed impeller is drawn. The results show that the flow field of the reconstructed impeller is uniform, and the pressure increases uniformly from the inlet to the outlet. The impeller pressure ratio is high, the efficiency is high and the impeller design is good under the fixed speed and back pressure. When the impeller speed is high, there is a certain degree of backflow and swirl at the tail edge of the impeller. 3. The strength and mode of impeller are analyzed by ANSYS Workbench software, and the maximum safe rotational speed of impeller is given. The results show that the maximum stress of the reconstructed impeller occurs at the hub near the center hole on the bottom end of the impeller. The maximum stress on the blade is concentrated at the front edge of the blade near the root of the blade. The amplitude of the front edge of the blade near the tip of the blade is the largest, and the possibility of local resonance is the greatest. Under the long-term action of unsteady aerodynamic load and other exciting forces, It is easy to form high cycle fatigue fracture at the leading edge of blade. 4. The strength and mode of impeller under fluid-solid coupling field are analyzed by ANSYS Workbench software. The results show that aerodynamic force has certain influence on the strength of impeller, aerodynamic force causes the stress of impeller to increase, but the deformation of impeller decreases slightly. The fluid-solid coupling field has little effect on impeller modes and can be neglected.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2012
【分类号】：TH136;TP391.72

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