離心泵作為一種通用的流體機(jī)械，在工業(yè)生產(chǎn)和日常生活中被廣泛的應(yīng)用。離心泵效率的提高會(huì)減少社會(huì)對(duì)能源需求的壓力。通過利用CFD對(duì)離心泵進(jìn)行數(shù)值模擬，預(yù)測(cè)離心泵性能、考察離其內(nèi)部流場(chǎng)，并提出了一種離心泵葉輪的切削方法，在滿足使用需要的同時(shí)，降低離心泵的揚(yáng)程，擴(kuò)大離心泵的使用范圍，提高離心泵的效率，從而達(dá)到節(jié)約能源的目的。具體工作從以下幾方面展開：

　　論述了課題的意義及研究背景，介紹了離心泵的種類結(jié)構(gòu)以及離心泵的應(yīng)用，列舉了目前常用離心泵研究方法及優(yōu)化方法，同時(shí)概括了本文主要的研究?jī)?nèi)容。

　　網(wǎng)格的一些基本概念，網(wǎng)格生成軟件Gridgen和PLOT3D格式文件。重點(diǎn)闡述了離心泵全流道六面體結(jié)構(gòu)網(wǎng)格的生成方法。針對(duì)離心泵的不同部件，綜合運(yùn)用Gridgen與Fortran相結(jié)合的辦法，完成了離心泵包括葉輪、蝸殼以及前后蓋板以外的密封部分六的面體結(jié)構(gòu)網(wǎng)格劃分。

　　CFD過程，包括前處理，求解和后處理。敘述了目前常用的湍流計(jì)算模型。本文提出選取SST湍流模型，結(jié)合k模型和k模型的優(yōu)點(diǎn)來對(duì)離心泵進(jìn)行數(shù)值模擬，并比對(duì)了模擬結(jié)果。接著FLUENT和Ansys CFX在離心泵模擬中的應(yīng)用。最后對(duì)不同的水模進(jìn)行了橫向?qū)Ρ取?/p>

　　對(duì)現(xiàn)有典型離心泵進(jìn)行內(nèi)流分析，考察了離心泵的速度場(chǎng)和壓力場(chǎng)的分布情況。然后對(duì)不同條件下對(duì)離心泵進(jìn)行數(shù)值模擬并分析結(jié)果，包括考慮到泄漏回流條件和不同入口條件下對(duì)離心泵數(shù)值模擬結(jié)果的影響。

　　闡述了現(xiàn)階段葉輪切割的一般方法，提出了一種只切削葉片，不切削前后蓋板的切削方法，可以降低離心泵揚(yáng)程。在滿足用戶需要的同時(shí)，提高離心泵的效率。利用CFD方法分析不同切削量下，離心泵的性能和內(nèi)流場(chǎng)的分布情況，對(duì)改善離心泵性能具有很大的現(xiàn)實(shí)意義。

　　最后對(duì)本文所做的工作進(jìn)行了總結(jié)，指出本文的創(chuàng)新點(diǎn)和不足之處，同時(shí)對(duì)這些不足之處的解決方法進(jìn)行了思考。

　　英文翻譯：As a kind of general fluid machinery, centrifugal pump is widely used in daily life and industrial production. It can reduce the pressure of energy demand when the efficiency of centrifugal pumps increase. In this thesis, several centrifugal pumps were studied to predict the performances and distributions of the internal flow field by using CFD method. In order to meet the practical needs, for example, to reduce the head of centrifugal pumps, a kind of centrifugal pump impeller cutting method was used in industrial practice. It can achieve the purpose of matching the specific application needs without changing a new pump. Several cut impellers were studied in this paper. The whole thesis consists of 6 chapters as follows:

　　The background and significance of the research is presented. The different kinds of centrifugal pumps and the application of them are introduced. The common methods of study and optimization are also discussed in this part. Then the main research contents are summarized.

　　The basic conception of grid is illustrated, including the software of grid generation named Gridgen and a file format named PLOT3D. The most important thing is the method of structure grid generation in a centrifugal pump. According to the different parts of the centrifugal pump, all the structure grids are accomplished including impeller part, volute part and the leakage part of the centrifugal pump by using a method of combining Gridgen with Fortran.

　　The process of CFD is introduced firstly. That is pre-processing, solver and post-processing. Then some commonly used turbulence models are introduced. SST and ??k turbulence model simulation results are compared, including the different commercial softwares of FLUENT and Ansys CFX. The last, the performances of different centrifugal pumps are studied.

　　The typical centrifugal pump is studied, including the distribution situations of velocity fields and pressure fields. And then, the numerical simulation results are analyzed in different conditions which include considering the leakage and different inlets.

　　A common method of cutting centrifugal pump impeller is introduced firstly. And then a kind of centrifugal pump impeller cutting method was put forward. That is the blades are cut only and ignored the impeller cover plates to reduce the head and increase the efficiency of centrifugal pumps based CFD numerical simulation. This method has a great practical significance to improve the performance of centrifugal pumps.

　　The thesis is summarized and the conclusion remarks are presented.