外文翻譯--研究一個(gè)離心泵內(nèi)的震動(dòng)壓力—利用數(shù)字表示的方法來支持工業(yè)實(shí)驗(yàn)

1、<p><b>　　英文文獻(xiàn)</b></p><p>　　Investigation into pressure pulsations in a centrifugal pump using numerical methods supported by industrial tests</p><p>　　R.Spence and J.Amaral-Teix

2、eira </p><p><b>　　ABSTRACT </b></p><p>　　The operation of centrifugal pumps can generate instabilities and pressure pulsations that may be detrimental to the integrity and performanc

3、e of the pump. In the present study a numerical investigation of the time variation of pressure within a complete pump was undertaken. A range of parameters and three flow rates were investigated and the pulsations were

4、extracted at 15 different locations covering important pump locations experiencing the largest pulsation levels. It was also note that moni</p><p>　　Introduction </p><p>　　Centrifugal pumps have

5、 been developed and refined over many years. In practice the design of both the impeller and volute are complex, with numerous geometrical parameters being required to identify a design that will form a hydraulically eff

6、icient pump. Even with tried designs it is well known that the operation of rotodynamic pump can result in the generation of the design process used; the final decision regarding the suitability of any significantly new

7、pump design is usually made following </p><p>　　Typically these investigations are conducted with a view to reducing, or eliminating the number of tests conducted and to highlight any undesirable design char

8、acteristics at an early stage. Although commercial CFD packages have been used to predict time dependent pressure pulsations, computational facilities seem to have limited most of that work to simulating the volute and i

9、mpeller interactions only, without the suction inlet branch and leakage flow paths being considered. The current work aim</p><p>　　The numerical model incorporates all of the major flow paths in a pump encom

10、passing the suction inlet, impeller, leakage pathways and the volute casing. The work focuses on a reduced scale version of a high energy impeller in a double entry, single stage pump arrangement. The understanding of pr

11、essure pulsations by pump manufacturers seems surprisingly limited. No official standards exist for safe levels of pressure pulsations in pumps; the only industry adopted guideline is a guarantee of less </p><

12、p>　　The analyses presented here are part of a large parametric study investigating the effect of internal geometry on pressure pulsations within the pump. Due to the constrains involved in such a large study, one addi

13、tional aim of this work was to show that a reasonable estimate of pressure pulsations and trends in pressure pulsations can be achieved, for differing pump geometries, in a reasonable time frame by numerical means.</p

14、><p>　　Experimental Investigation </p><p>　　Some experimental results were available to one of the authors from industrial tests performed to examine pressure pulsations in a reduced scale contract

15、 pump. This experimental work performed a number of years before the numerical analyses. The pump received fluid from a closed system, such that the pump was situated with a bend 3.5 diameters upstream and a second bend

16、4 diameters downstream. Directly following the upstream bend, flow straighteners were fitten in order to reduce the flow effect</p><p>　　One Z type Entran pressure transducer was utilized in the experimental

17、 tests. This transducer was mounted in the impeller shroud 15omm behind the suction face of an impeller blade. The electrical signals from the transducers were transferred from the rotating element the stationary data re

18、corder via a slip ring arrangement at the non-drive end of the pump. The test ring was run at an initial speed of 1400RPM over the flow range 25-125%of duty with 5-min tape recordings of the transducers being t</p>

19、<p>　　Due to the time constraints involved in the experimental tests, detailed performance data was not taken. The test work was conducted in accordance with normal industrial practices and it is considered that t

20、he pressures were accurate within 1.5%.</p><p>　　Numerical Investigation </p><p>　　CFX-TASC flow is a commercial 3D-CFD code that a finite-element based finite-volume method to the transport equ

21、ations. This method provides the benefit of retaining the geometric flexibility of finite-element methods while retaining the conservation properties of the finite-volume method, I, e low numerical error on non-smooth gi

22、rds. The code employs co-located structured grids and a coupied algebraic multigrid scheme to solve the system of equations. It is a fully-implicit solver, thus it creat</p><p>　　3、1 Model generation </p&

23、gt;<p>　　The impeller geometry was created using CFX-Bladehen as two mirrored halves, using the maximum diameter of 366omm. The bull-nose aspect of the inline impeller design proved difficult to capture within CFX

24、-Bladegen, as the program is not designed to model double entry impeller and does not allow for hub profiles that terminate in the bull nose arrangement. To avoid this problem, although the true hub effectively finished

25、at the point of symmetry, a fictitious hub was extended from the midpoint of</p><p>　　CFX-Turbogrid was used to generate grid around the blades on either side of the impeller, with the grid on both sides of

26、the impellers being identical. For the inline impeller, care was taken to ensure that the grid was radial at the position of the bull nose. This is essential to aid the creation of an interface between the impellers in C

27、FX-TASC flow, however it also limited the quality of the grid. With an initial impeller grid estimate of around 500,000 modes, it is immediately apparent that </p><p>　　4、2 Solution parameters</p><

28、;p>　　As the motion of the impeller blades relative to the stationary volute is central to the investigation, the analysis must involve multiple frames of reference. In order to prevent two rotor/stator interfaces bein

29、g perpendicular to each other at the ompeller outlet, the leakage flow paths and the impeller grids were set in the rotational frame of reference. The suction inlet and volute grids were in the stationary frame of refere

30、nce. The grid interfaces used in the study can be summarized as foll</p><p>　　Internal component connection : general grid interface(GGI)</p><p>　　Between two stationary components: general grid

31、 interface</p><p>　　Between two rotational components: general grid interface</p><p>　　Between rotational and stationary components:</p><p>　　Frozen rotor interface (steady state an

32、alysis)</p><p>　　Rotor/stator interface (transient analysis)</p><p>　　The frozen rotor interface achieves frame change without relative position change over time and without interfacial averagin

33、g. Local flow features are allowed to propagate. A physical analogy is to imagine observing the flow between a stationary and rotating component under stroboscopic lighting. The rotor/stator interface is a sliding(frame

34、change) interface that can account for transient interaction effects. The mesh on either side of a rotor/stator interface is always in relative motion with </p><p>　　Inlet: total pressure “Outlet: mass flow”

35、</p><p>　　Inlet: mass flow “Outlet: static pressure”</p><p>　　Inlet: total pressure “Outlet: static ptessure”</p><p>　　The transient analysis was conducted for three flow rates. The

36、se are defined as being the duty flow condition (1.00oQn), 0.50oQn and 0.25oQn. Turbulence has been simulated using the standatdk-epsilon model. An investigation was conducted into various turbulence models and the stand

37、ard k-epsilon model was found to be more stable and produce better results than other models over the flow range being considered. The grid size used in the analysis is not capable of modeling local boundary layers hen&l

38、t;/p><p><b>　　中文翻譯</b></p><p>　　研究一個(gè)離心泵內(nèi)的震動(dòng)壓力—利用數(shù)字表示的方法來支持工業(yè)實(shí)驗(yàn)</p><p><b>　　摘要</b></p><p>　　離心泵的操作會(huì)產(chǎn)生不穩(wěn)定性和震動(dòng)壓力，這可能有害于泵的完整性和其他性能。當(dāng)前，正在研究一個(gè)承受于整個(gè)離心泵內(nèi)部，

39、隨時(shí)間變化的壓力。計(jì)算出參數(shù)的范圍和三個(gè)流動(dòng)速度，并且在泵的15個(gè)被覆蓋不同的重要地方萃取震動(dòng)。瞬變流動(dòng)導(dǎo)致在一個(gè)小范圍試驗(yàn)測量所獲取的結(jié)果與明顯的顯示泵的位置經(jīng)歷大的震動(dòng)水平相比較。這也說明，在泵渦形保護(hù)套的上死點(diǎn)對(duì)泵內(nèi)在震動(dòng)的保護(hù)要比在流動(dòng)中更好。</p><p><b>　　1、介紹</b></p><p>　　離心泵早已被發(fā)明，并且精確度超過了很多年前。在實(shí)踐

40、中，葉輪和渦螺的設(shè)計(jì)是一個(gè)整體，利用大量必要的幾何學(xué)參數(shù)驗(yàn)證這個(gè)設(shè)計(jì)這將會(huì)產(chǎn)生一個(gè)水利的效率泵。眾所周知，用試驗(yàn)就能導(dǎo)致操作動(dòng)態(tài)泵時(shí)產(chǎn)生震動(dòng)壓力。</p><p>　　不管習(xí)慣的設(shè)計(jì)過程，任何重要的新泵設(shè)計(jì)最后能相匹配的結(jié)果通常都是跟隨物理實(shí)驗(yàn)。這些實(shí)驗(yàn)在時(shí)間和資金上常常都有較大的花費(fèi)。例如，由于制造業(yè)的模型裝置，原裝泵也可以裝配和利用實(shí)驗(yàn)設(shè)備。逐漸地，泵制造廠商把計(jì)算法轉(zhuǎn)向機(jī)構(gòu)特點(diǎn)。</p>&l

41、t;p>　　引導(dǎo)這些與代表性的研究著眼于減少體重法，或者排除實(shí)驗(yàn)中的數(shù)據(jù)，并且，在早期發(fā)展的進(jìn)程中給任何不合需要的加亮燈設(shè)計(jì)特點(diǎn)。雖然，商業(yè)的CFD包裹以前習(xí)慣依靠震動(dòng)壓力來預(yù)測時(shí)間，但是，計(jì)算設(shè)備似乎已經(jīng)限制于大量工作而僅模擬渦螺和葉輪的交互作用?？紤]到?jīng)]有吸入口的輸入支管和泄流流程。當(dāng)前的工作目的是去改進(jìn)和以前的工作范圍，涉及由于模擬產(chǎn)生的震動(dòng)壓力，包括完整的水泵幾何學(xué)。</p><p>　　數(shù)字模擬合

42、并了所有泵中主修的流動(dòng)流程，環(huán)繞著吸入口，葉輪，泄露管徑和渦螺保護(hù)套。工作集中于縮小在雙力高壓葉輪的比例，單向多極泵的排列。通過泵的制造商對(duì)泵震動(dòng)壓力的理解似乎驚人的有限。對(duì)于泵中震動(dòng)壓力安全水平?jīng)]有正式的標(biāo)準(zhǔn)，只有工業(yè)上會(huì)采用保證比泵出口壓力小百分之3的方針。然而，不知道一個(gè)在泄流處相應(yīng)百分之3的限度在其他泵內(nèi)裝置上是否是安全限度。因此，在葉輪和渦螺中對(duì)震動(dòng)壓力詳細(xì)的估計(jì)已經(jīng)完全被測量，無論在泄流處百分之三的限度是否被采用，實(shí)際上都已

43、給與泵的其他主要機(jī)件所有保證。分析包括三個(gè)流動(dòng)速度超過流動(dòng)范圍從一個(gè)要求泵輸送量流速范圍伸出到一個(gè)普通泵最小操作點(diǎn)的百分之25。這里的分析只是大量參數(shù)的一部份，研究泵內(nèi)部震動(dòng)壓力幾何學(xué)的影響。這次工作的另一個(gè)目的是表示震動(dòng)壓力合理的估計(jì)和震動(dòng)壓力能夠被獲得的傾向，因?yàn)椴煌谋玫膸缀螌W(xué)，通過數(shù)字表示的方法在一個(gè)合理的期限內(nèi)。</p><p><b>　　2、試驗(yàn)研究</b></p>

44、<p>　　工業(yè)試驗(yàn)者可以利用一些試驗(yàn)的結(jié)果，檢查縮小比例泵的震動(dòng)壓力。這些試驗(yàn)在數(shù)字分析之前就使用了很多年了。泵被承認(rèn)的流動(dòng)是從一個(gè)閉式系統(tǒng)，這種泵位于上游3.5個(gè)距離，下游4個(gè)距離。直接的在上游彎曲之后，直流被使用于為了減少流動(dòng)因素導(dǎo)致流入泵中。十個(gè)Z類型的壓力是裝在泵上的。</p><p>　　壓力被用來收集數(shù)據(jù)，在各個(gè)固定地點(diǎn)周圍的泵。孔鉆在特定的地點(diǎn)靠近泵和管用于連接壓力傳感器，以每個(gè)地點(diǎn)

45、。路徑距離出鐵點(diǎn)指向該傳感器是保持盡可能短（ 10-15毫米） ，以確保任何共振頻率所造成的路徑距離是上述的測量范圍。</p><p>　　一Z型壓力傳感器是利用在實(shí)驗(yàn)測試。這個(gè)傳感器是安裝在葉輪遮掩物15毫米背后的吸力面對(duì)一個(gè)葉輪葉片。電氣信號(hào)從傳感器被移送從旋轉(zhuǎn)元素，固定數(shù)據(jù)記錄器通過滑環(huán)安排在非驅(qū)動(dòng)器末端泵。該試驗(yàn)臺(tái)是運(yùn)行在一個(gè)初步的速度，每分鐘轉(zhuǎn)速超過1400年的流量范圍25-125 ％，與5分鐘錄音的傳

46、感器正在采取在每25 ％的流量增量。該1.00 條件等同流速500立方米每小時(shí)和象征性帶頭點(diǎn)33.8米為內(nèi)插時(shí)，葉輪泵的運(yùn)行在1400 RPM的。流量變化所取得的調(diào)整一流量閥，使它盡可能的緩慢、平滑。一系列的測試，表現(xiàn)為一些泵的幾何安排，但只有兩個(gè)是在這里特別有興趣的（被稱為A和B作為詳細(xì)以上） 。一個(gè)時(shí)間歷史的壓力變化，在上述每個(gè)地點(diǎn)都是有記錄的。 1譜分析，當(dāng)時(shí)進(jìn)行的這一數(shù)據(jù)與壓力脈動(dòng)被輸出作為的均方根（ RMS的）壓力脈動(dòng)。 由

47、于時(shí)間限制，所涉及的實(shí)驗(yàn)測試，詳細(xì)的性能數(shù)據(jù)沒有考慮。測試工作的進(jìn)行，在按照正常的工業(yè)做法，這是認(rèn)為，壓力是準(zhǔn)確的± 1.5 ％ 。</p><p>　　3、數(shù)值調(diào)查利用CFX終端區(qū)域時(shí)序控制流量是一個(gè)商業(yè)三維的CFD代碼，采用有限元為基礎(chǔ)的有限體積法，以運(yùn)輸方程。這種方法提供，保留幾何的靈活性，有限元方法，同時(shí)保留養(yǎng)護(hù)性能的影響有限體積法，即低的數(shù)值誤差對(duì)非光滑的網(wǎng)格。該守則擁有在同一地點(diǎn)的結(jié)構(gòu)網(wǎng)格

48、和耦合的代數(shù)多重計(jì)劃，以解決系統(tǒng)的方程。這是一個(gè)完全隱式求解方法，因此，造成沒有時(shí)間和步驟的限制，被認(rèn)為很容易執(zhí)行。這并不是任何影響穩(wěn)定的國家的解決辦法，但這限制暫態(tài)計(jì)算，只有第一階準(zhǔn)確的時(shí)間。該利用CFX終端區(qū)域時(shí)序控制流量求解也是一個(gè)耦合求解，即勢頭和連續(xù)性方程的解決同時(shí)進(jìn)行。這種做法減少了迭代次數(shù)須獲得的收斂性和沒有壓力校正來說，是需要保留的質(zhì)量守恒，導(dǎo)致了更強(qiáng)有力的和準(zhǔn)確的求解。該計(jì)劃還包括一些會(huì)前和會(huì)后處理能力，是專門面向葉輪

49、機(jī)械零件;這些方便成立了該模型和考試的結(jié)果。利用CFX終端區(qū)域時(shí)序控制流量已經(jīng)經(jīng)過驗(yàn)證的追蹤記錄在葉輪機(jī)械的應(yīng)用，項(xiàng)目眾多的文學(xué)出版。</p><p>　　3．1、模型生成葉輪幾何創(chuàng)建使用利用CFX刀刃作為兩個(gè)鏡像邊，使用最大直徑366毫米。牛鼻方面的內(nèi)插葉輪設(shè)計(jì)證明，很難捕捉與利用CFX刀刃，作為該計(jì)劃并非設(shè)計(jì)用來模型雙進(jìn)入葉輪，并且不允許為樞紐的配置文件，終止在牛市的鼻子安排。為了避免這個(gè)問題，雖然真正的樞

50、紐，有效地完成在點(diǎn)對(duì)稱性，一個(gè)虛構(gòu)的樞紐延長至中點(diǎn)牛鼻葉輪出口沿葉輪線的對(duì)稱性。因此，只有輕微的修改，經(jīng)向樞紐簡介一個(gè)令人滿意的模型制作內(nèi)嵌葉輪。交錯(cuò)葉輪可用于無任何修改，由于子午流徑，任何一方的葉輪不連接。</p><p>　　利用CFX網(wǎng)格來生成網(wǎng)格周圍的葉片對(duì)任何一方的葉輪，與網(wǎng)格兩邊的葉輪被完全相同。為內(nèi)插葉輪，護(hù)理是采取措施，確保網(wǎng)格是在徑向的立場牛鼻。這是必需的援助，建立一個(gè)界面之間的葉輪在利用CFX

51、終端區(qū)域時(shí)序控制流量，但它也限制了高質(zhì)量的網(wǎng)格。與初步葉輪網(wǎng)格估計(jì)約五十萬節(jié)點(diǎn)，這是立即明顯的分裂，這12個(gè)網(wǎng)格之間的葉輪通道和泄漏流將導(dǎo)致在葉輪通道網(wǎng)格低于理想的大小。一些已作出努力集中于較小的網(wǎng)格大小，而包括網(wǎng)格大如86499節(jié)點(diǎn)。由于葉輪的互動(dòng)與蝸殼是非常重要的，決定進(jìn)行網(wǎng)格的獨(dú)立檢查是否使用了穩(wěn)定狀態(tài)的分析納入模型構(gòu)成的一半，一個(gè)水泵，即6葉輪通道和二分之一泵蝸殼（利用對(duì)稱性）。蝸殼模型是一致的，在每個(gè)網(wǎng)格的獨(dú)立分析，與分布相似

52、，所用的最后泵模型。可以預(yù)料，這種相互作用會(huì)引起較大的分歧很明顯之間的網(wǎng)格比通常顯示在網(wǎng)格獨(dú)立的葉輪，只有比較，由于日趨復(fù)雜的流通模式。由分析來說，在工作地點(diǎn)的水流條件（1.00qn），邊界條件，正在大規(guī)模流進(jìn)和平均靜態(tài)壓力的插座，與最高殘余收斂準(zhǔn)則被設(shè)定為1e-4（最大值） 。壓力數(shù)據(jù)報(bào)告，下面涉及到的變異在一個(gè)單一的葉輪通道（從中間通過）在一個(gè)單一的地位，蝸殼。</p><p>　　3.2、解決參數(shù)由于該議

53、案的葉片相對(duì)平穩(wěn)蝸殼是中環(huán)至調(diào)查，分析必須涉及多個(gè)參照系。 ，以防止兩個(gè)轉(zhuǎn)子/定子接口正在互相垂直于葉輪出口，泄漏流的路徑和葉輪的網(wǎng)格定在轉(zhuǎn)動(dòng)的參照系。吸力進(jìn)氣道和蝸殼網(wǎng)格在靜止的參照系。網(wǎng)格接口中使用的研究可歸納如下： 內(nèi)部組件方面：一般的網(wǎng)格界面（ ggi ） 兩國固定組成部分：一般的網(wǎng)格界面之間的兩個(gè)轉(zhuǎn)動(dòng)分量：一般的網(wǎng)格界面之間的旋轉(zhuǎn)和固定部分組成：  凍結(jié)轉(zhuǎn)子接口（穩(wěn)態(tài)分析）  轉(zhuǎn)子/定子接口（瞬

54、態(tài)分析） 被凍結(jié)的轉(zhuǎn)子界面實(shí)現(xiàn)框架沒有改變的相對(duì)位置隨時(shí)間變化和界面平均。本地流動(dòng)的特點(diǎn)是允許運(yùn)輸全國界面，因此，壓力非一致結(jié)構(gòu)允許宣傳。身體的比喻是想象觀測流量之間的固定和旋轉(zhuǎn)構(gòu)件下的頻閃照明。轉(zhuǎn)子/定子界面是一個(gè)滑動(dòng)（幀改變）接口，可以帳目瞬態(tài)的互動(dòng)效果。網(wǎng)格兩側(cè)的轉(zhuǎn)子/定子界面始終是在相對(duì)運(yùn)動(dòng)與尊重，到另一個(gè)。 有三種常見的組合邊界條件往往是用于分析水泵流量。 進(jìn)氣道：總壓出路：質(zhì)量流量進(jìn)氣道：質(zhì)量流量出路：靜壓力進(jìn)氣道