《离心泵压力脉动的特性分析和测试分析研究机械制造专业》由会员分享，可在线阅读，更多相关《离心泵压力脉动的特性分析和测试分析研究机械制造专业（68页珍藏版）》请在金锄头文库上搜索。
1、摘要离心泵在产生静态压力分量的同时还产生动态压力分量，也就是压力脉动，压力脉动象交流信号一样叠加在静态压力分量上。离心泵大多采用螺旋型蜗壳 ，蜗壳与隔舌的不对称性造成叶轮出口流动的环形畸变，尤其是在非设计工况点时，畸变更为剧烈，因此在设计主轴时，必须考虑由于压力分布不平衡引起的脉动特性。离心泵内的压力脉动是极其复杂的，对同一台泵，不同工况呈现不同性质的压力脉动。泵内部流场非定常的湍流特性、叶轮与进水管的动静干扰、涡流及回流等都可能引起压力脉动，该压力脉动激发泵体和管道的机械振动，影响泵的正常运转，降低了泵的使用寿命；如果这种激励振动的频率接近泵的主频，还会发生共振，振动会在相邻的环境介质内产生
2、声压波动，产生很大的噪声。可见，泵内压力脉动是影响水泵运行稳定性的重要因素，也是导致噪声污染的重要原因。因而，对泵内部压力脉动进行研究，降低泵的振动噪声成为当前研究的重要任务之一。本文首先应用CFD（Computational Fluid Dynamics）技术Fluent软件 ，在多工况下同时监测叶轮流道与蜗壳内压力脉动的情况，以揭示压力脉动与离心泵性能之间的关系，为进一步预测离心泵非定常流动诱发压力脉动提供依据。为了研究离心泵在不同工况下以及不同位置间压力脉动的变化规律及其关系，基于标准 k-湍流模型和滑移网格模型，应用Fluent软件对离心泵内部流场先后进行定常与非定常三维模拟，得到大致
3、的内部流场特性及监测点的压力脉动情况。计算结果表明：在小流量工况下，由于内部流场的不稳定运行各监测点处的压力脉动都比较大且不均匀；在叶轮流道中，接近叶轮出口处的压力脉动明显高于叶轮流道其他区域压力脉动。大流量工况下在蜗壳隔舌和出口处会产生一定回流导致蜗壳该处附近压力脉动表现不稳定。蜗壳隔舌处由于该位置流域比较复杂压力脉动较大；蜗壳出口处的波动情况非常平缓，这主要是因为蜗壳出口段的缓冲与稳流作用。其次进行测量系统的方案设计，先对压力变送器和数据采集模块的参数进行充分的了解，完成二者的硬件选型以及电路接线图的构造。再利用Labview软件编写上位机界面，通过设置采样频率、采样数据点、采集量程等操作
4、完成8条通道数据的采集和曲线的显示，且保存数据。关键词：离心泵，压力脉动，定常模拟，非定常模拟，上位机界面15AbstractCentrifugal pump produces static pressure components and produces dynamic pressure components，that is，pressure pulsation. Pressure pulsation is superimposed on static pressure components just like AC signals. Most of the spiral volute ce
5、ntrifugal pump，volute ring distortion and asymmetry of the tongue caused by impeller exit flow，especially in the non design condition，the distortion is more violent，so in the design of the spindle，the pressure must be due to the unbalanced distribution of fluctuation caused by considering. The press
6、ure pulsation in the centrifugal pump is extremely complex，and the pressure pulsation of the same pump is different in different working conditions. Pump internal flow field and unsteady turbulent characteristics，the impeller and the water inlet pipe of the rotor stator interaction，eddy current and
7、reflux may cause pressure pulsation，mechanical vibration of the pressure pulsation excitation pump and pipeline，affect the normal operation of the pump，reduce the service life of the pump； if the excitation frequency is close to the frequency of the pump. The resonance vibration will occur，will prod
8、uce pressure fluctuations in the ambient medium adjacent，have a great noise. It can be seen that the pressure pulsation in the pump is an important factor affecting the stability of the pump operation，and is also an important cause of noise pollution. Therefore，it is one of the important tasks to st
9、udy the pressure pulsation in the pump and reduce the vibration noise of the pump.This paper first applies CFD technology FLUENT software to monitor the pressure pulsation in impeller and volute simultaneously under multiple conditions，so as to reveal the relationship between pressure pulsation and
10、centrifugal pump performance，and provide a basis for further prediction of unsteady flow induced pressure pulsation in centrifugal pumps. In order to study the centrifugal pump under different working conditions and the variation of pressure fluctuation between different locations and their relation
11、ship，standard k- turbulence model and sliding mesh model based on the application of FLUENT software on the internal flow field of centrifugal pump has steady and unsteady three-dimensional simulation，get the pressure pulsation of internal flow characteristics and monitoring points of the roughly. T
12、he calculation results show that under the condition of small flow rate，the pressure pulsation at each monitoring point is large and uneven due to the unstable internal flow field，and the pressure pulsation near the impeller outlet is significantly higher than that in other regions of impeller passa
13、ge. Under the large flow condition，there will be a certain reflux in the tongue and outlet of the volute，which results in the instability of the pressure fluctuation near the worm shell. Because of the complex pressure pulsation at the location of the basin，the fluctuation of the outlet of the volut
14、e is very gentle，which is mainly due to the buffering and steady flow of the outlet section of the volute.On the other hand，on the design of the measurement system，we fully understand the parameters of the pressure transmitter and data acquisition module，and complete the hardware selection of the tw
15、o parts and the construction of the wiring diagram. Then we use LabVIEW software to write the upper machine interface. We set up sampling frequency，sampling data points and collecting ranges to complete the 8 channel data collection and curve display，and save data.Keywords：centrifugal pump, pressure
16、 fluctuation, Constant simulation, Unsteady simulation, Unsteady simulation目录目录摘要IAbstractII第一章 绪论11.1 课题的研究背景及意义11.2 国内外研究现状21.2.1 国外研究现状21.2.2 国内研究进展31.3 论文工作的主要内容4第二章 泵内流动数值计算方法及压力脉动的相关理论52.1 离心泵的三维建模52.1.1 叶轮实体模型的建立52.1.2 蜗壳实体模型的建立62.1.3 进水管实体模型的建立72.1.4 元件的装配82.2 数值计算方法概述92.2.1 流动控制方程102.2.2 旋转区域中流动问题的建模122.2.3 湍流模型132.2.4 求解控制142.3 离心泵的网格划分152.3.1 网格相关问题的概述152.3.2 网格划分162.4 离心泵压力脉动的分类1
