本文關(guān)鍵詞：離心水泵的優(yōu)化設(shè)計及其仿真　出處：《西北農(nóng)林科技大學(xué)》2011年碩士論文　論文類型：學(xué)位論文

  更多相關(guān)文章： 離心泵 多目標優(yōu)化 葉輪和蝸殼匹配耦合 數(shù)值模擬

【摘要】：離心泵廣泛應(yīng)用于國民經(jīng)濟和社會生活的各個領(lǐng)域,在石油、化工、冶金、城市給排水、農(nóng)業(yè)灌溉等領(lǐng)域發(fā)揮著重要的作用。隨著計算機技術(shù)和流體動力學(xué)(CFD)技術(shù)的發(fā)展,人們對離心泵的性能要求也越來越高�，F(xiàn)階段離心泵的優(yōu)化設(shè)計大多數(shù)是單目標優(yōu)化且沒有考慮葉輪和蝸殼的匹配關(guān)系,流場模擬忽略了葉輪和蝸殼間的耦合特性,導(dǎo)致離心泵的優(yōu)化設(shè)計結(jié)果不甚理想。本文的研究方法和內(nèi)容對于改善離心泵性能和完善離心泵優(yōu)化設(shè)計理論具有借鑒意義。 本文以低比轉(zhuǎn)速離心泵為研究對象,建立了離心泵的損失、汽蝕性能和穩(wěn)定性的多目標優(yōu)化數(shù)學(xué)模型,采用Matlab遺傳算法工具箱進行優(yōu)化計算。根據(jù)優(yōu)化后的幾何參數(shù)建立離心泵的流場模型并進行了網(wǎng)格劃分和邊界條件設(shè)定。數(shù)值模擬離心泵全流場以及葉輪和蝸殼耦合特性并預(yù)測了其揚程和效率等性能指標。 考慮離心泵葉輪和蝸殼間的匹配關(guān)系,確定最佳工況點下的理論揚程;建立了以離心泵的能量損失、汽蝕性能和H -Q曲線無駝峰的多目標優(yōu)化數(shù)學(xué)模型,并根據(jù)分目標函數(shù)的重要性不同,利用線性加權(quán)法統(tǒng)一目標函數(shù);確定了適合本研究問題的優(yōu)化變量范圍。 采用Matlab遺傳算法工具箱進行優(yōu)化計算,得出離心泵幾何參數(shù)的最優(yōu)組合解,使離心泵的能量損失減少了1130.7w,汽蝕余量降低了0.4258m,離心泵的H -Q曲線穩(wěn)定性也有很大的改善,理論分析優(yōu)化結(jié)果的可行性。 采用Pro/ENGINEER軟件進行離心泵的葉輪和蝸殼三維流場的建模,使用CFD前處理軟件Gambit對離心泵整機三維流場模型進行網(wǎng)格劃分,確定了邊界條件和流體類型。選擇Fluent軟件對離心泵的整體三維流場以及葉輪和蝸殼間的耦合特性進行數(shù)值模擬。 選擇Fluent的后處理功能得到了離心泵內(nèi)部全流場壓力云圖、速度矢量以及葉輪和蝸殼耦合面上的速度矢量圖;分析了不同工況下離心泵內(nèi)部全流場的壓力和速度分布的變化;從數(shù)值模擬數(shù)據(jù)中導(dǎo)出離心泵進出口處的壓力和葉輪繞Z軸的力矩,對離心泵的理論揚程和效率進行性能預(yù)測,進一步驗證了數(shù)值模擬和優(yōu)化設(shè)計的正確性。 本文將多目標優(yōu)化設(shè)計、遺傳算法和CFD流場數(shù)值模擬結(jié)合起來,對改善離心泵的整機性能和研究全流場的復(fù)雜運動規(guī)律具有重要的借鑒意義。
[Abstract]:Centrifugal pumps are widely used in various fields of national economy and social life, in petroleum, chemical, metallurgy, urban water supply and drainage. Agricultural irrigation and other fields play an important role. With the development of computer technology and fluid dynamics (CFDs) technology. At this stage, the optimization design of centrifugal pump is mostly single-objective optimization and does not consider the matching relationship between impeller and volute. The coupling between the impeller and the volute is neglected in the flow field simulation. The research methods and contents of this paper are useful for improving the performance of centrifugal pump and improving the theory of optimal design of centrifugal pump. In this paper, a multi-objective optimization mathematical model of centrifugal pump's loss, cavitation performance and stability is established. Matlab genetic algorithm toolbox is used for optimization calculation. According to the optimized geometric parameters, the flow field model of centrifugal pump is established, and the grid and boundary conditions are set up. The full flow field of centrifugal pump is simulated numerically. The coupling characteristics of impeller and volute are predicted and the performance indexes such as lift and efficiency are predicted. Considering the matching relationship between impeller and volute of centrifugal pump, the theoretical head at the best working condition is determined. A multi-objective optimization mathematical model with energy loss, cavitation performance and H-Q curve without hump of centrifugal pump is established. According to the importance of sub-objective function, linear weighting method is used to unify the objective function. The range of optimization variables suitable for this problem is determined. By using Matlab genetic algorithm toolbox, the optimal combination solution of geometric parameters of centrifugal pump is obtained, and the energy loss of centrifugal pump is reduced by 1130.7w. The cavitation margin is reduced by 0.4258m, and the stability of H-Q curve of centrifugal pump is improved greatly. The three-dimensional flow field of impeller and volute of centrifugal pump is modeled by Pro/ENGINEER software. The three-dimensional flow field model of centrifugal pump was meshed with CFD pre-processing software Gambit. The boundary conditions and fluid types are determined, and the whole three-dimensional flow field of centrifugal pump and the coupling characteristics between impeller and volute are numerically simulated with Fluent software. The post-processing function of Fluent is selected to obtain the pressure cloud diagram, velocity vector and velocity vector diagram on the coupling surface of impeller and volute in the whole flow field of centrifugal pump. The variation of pressure and velocity distribution in the whole flow field of centrifugal pump under different working conditions is analyzed. The pressure at the inlet and outlet of the centrifugal pump and the torque of the impeller around the Z axis are derived from the numerical simulation data. The theoretical head and efficiency of the centrifugal pump are predicted, which further verifies the correctness of the numerical simulation and the optimization design. In this paper, the combination of multi-objective optimization design, genetic algorithm and numerical simulation of CFD flow field is of great significance for improving the performance of centrifugal pump and studying the complex motion law of the whole flow field.
【學(xué)位授予單位】：西北農(nóng)林科技大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2011
【分類號】：TH311

【引證文獻】

相關(guān)碩士學(xué)位論文 前1條

1 李燕平;離心風(fēng)機葉輪的有限元分析及優(yōu)化[D];西北農(nóng)林科技大學(xué);2012年

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本文編號：1414790