空氣濾清器外文翻譯

1、學(xué)校代碼：11517學(xué) 號：201250616134henan institute of engineering文獻(xiàn)翻譯題 目東風(fēng)日產(chǎn)陽光轎車空氣濾清器的設(shè)計學(xué)生姓名李明陽專業(yè)班級機(jī)械設(shè)計制造及其自動化1222班學(xué) 號 學(xué)1250616134院（部）機(jī)械工程學(xué)院指導(dǎo)教師（職稱）楊建偉（副教授）完成時間 2014年2月26日一個用于內(nèi)燃發(fā)動機(jī)進(jìn)氣系統(tǒng)的無聲空氣濾清器的虛擬設(shè)計及性能預(yù)測一個用于內(nèi)燃發(fā)動機(jī)進(jìn)氣系統(tǒng)的無聲空氣濾清器的虛擬設(shè) 計及性能預(yù)測hao zhi-yong, jia wei-xin, fang fang(college of mechanical and energy engin

2、eering, zhejiang university, hangzhou 310027, china)(tianjin internal combustion engine research institute, tianjin university, tianjin 300072,china)e-mail: ; received jan. 17, 2005; revision accepted may 12, 2005摘要：本文報道中采用低噪聲內(nèi)燃機(jī)進(jìn)氣系統(tǒng)開發(fā)的虛擬設(shè)計方法結(jié)合作者的研究結(jié)果。由此產(chǎn)生的高的通過噪聲水平高于在全油

3、門的立法目標(biāo)時，發(fā)動機(jī)轉(zhuǎn)速為5200 r/min需要邊界元輔助設(shè)計任務(wù)，按照典型的進(jìn)氣系統(tǒng)的設(shè)計與開發(fā)過程。在最初的設(shè)計中，基于聲學(xué)理論和要求并考慮空間發(fā)動機(jī)室中的約束，總體積和粗糙的內(nèi)部尺寸的測定。在詳細(xì)設(shè)計階段，確定了空氣濾清器的確切的內(nèi)部尺寸，和一個有效的方法應(yīng)用于低頻聲性能的改善。預(yù)測表明，進(jìn)氣系統(tǒng)的聲功率達(dá)到最小的進(jìn)氣系統(tǒng)噪聲降低發(fā)動機(jī)整體噪聲。關(guān)鍵詞：虛擬設(shè)計；聲學(xué)t能；沉默的空氣濾清器；邊界元法(bem)1簡介一個原函數(shù)的進(jìn)氣系統(tǒng)的主要功能是首先有效信道的新鮮空氣對發(fā)動機(jī)進(jìn) 氣噪聲，其次是減少排放。有一些現(xiàn)有方法的發(fā)展來提高進(jìn)氣系統(tǒng)設(shè)計一個更現(xiàn) 實(shí)的方法。這些目標(biāo)包括：更有效的消

4、聲性能，達(dá)到降低噪聲一方面日益嚴(yán)峻的 立法目標(biāo)，優(yōu)化發(fā)動機(jī)的性能和燃油經(jīng)濟(jì)性伴隨著車輛質(zhì)量的提高。一個典型的程序，用于汽車發(fā)動機(jī)進(jìn)氣系統(tǒng)的設(shè)計與開發(fā)過程中。設(shè)計過程包括仔細(xì)調(diào)諧的匹配這些發(fā)動機(jī)運(yùn)行和呼吸特性的影響，污染物排放優(yōu)化影響噪聲進(jìn)氣系統(tǒng)的所有組件，性能和經(jīng)濟(jì)性。從現(xiàn)有的或符號的系統(tǒng)布局，進(jìn)行各種 性能綜合評價。這種信息可能會被適當(dāng)?shù)厥褂迷u估的各種設(shè)計目標(biāo)當(dāng)前系統(tǒng)的性 能，通過對其構(gòu)成要素進(jìn)行適當(dāng)修改，為系統(tǒng)優(yōu)化設(shè)計提供理論基礎(chǔ)。邊界元法廣泛應(yīng)用在進(jìn)氣和排氣系統(tǒng)的設(shè)計可以用來計算內(nèi)部，外部，或兩個領(lǐng)域的同時，只要求的空氣濾清器可分為元素的周長；和施加邊界條件的緩解 是另一個吸引。在本文中

5、，邊界元法是用來預(yù)測的空氣濾清器的傳輸損耗和噪聲 排放。原來的進(jìn)氣系統(tǒng)設(shè)計中出現(xiàn)的水平高于在全油門和發(fā)動機(jī)轉(zhuǎn)速在5200r/min的噪聲信號的頻譜特性的立法目標(biāo)噪聲高通連接通常是由離散的音調(diào)，對發(fā)動機(jī)的點(diǎn)火頻率是173赫茲對應(yīng)5200 r/min內(nèi)聯(lián)四缸四沖程發(fā)動機(jī)諧波相關(guān)的廣泛的 序列占主導(dǎo)地位。在許多情況下，從主源的聲能量體分布較低的頻率成分， 可能 是難以控制的。因此，本文提到的頻率范圍是從0到1千赫。在這個頻率范圍內(nèi)， 如濾紙對集成系統(tǒng)的聲學(xué)性能的影響是微不足道的，所以濾紙不顧。噪音是從空氣濾清器入口噴出，與空氣濾清器系統(tǒng)出口連接到發(fā)動機(jī)的進(jìn)氣。 所以在發(fā)動機(jī) 空氣濾清器的出入口壓力為

6、邊界元法的邊界條件。一個降噪通常有兩部分功能的傳統(tǒng)進(jìn)氣系統(tǒng)：空氣濾清消聲器。由于空間發(fā) 動機(jī)室中的約束，重新設(shè)計的空氣凈化器結(jié)合清洗和沉默效果。在這項(xiàng)工作中， 一個所謂的沉默的空氣濾清器進(jìn)行了重新設(shè)計，幾何結(jié)構(gòu)確定的預(yù)測tl和邊界元的聲功率發(fā)射。同時，為了盡量減少在較低頻率的進(jìn)氣系統(tǒng)的聲功率， 旁通管 被添加到空氣輸送管。所產(chǎn)生的聲學(xué)性能分析表明，該方法最大限度地減少對進(jìn) 氣系統(tǒng)噪聲降低發(fā)動機(jī)整體噪聲的目標(biāo)是可行的。2無聲空氣濾清器的設(shè)計2.1 原裝空氣濾清器的評價這種原始的空氣濾清器的清潔設(shè)計主要關(guān)注減少噪音排放?？諝鉃V清器的出口段是一個單位的速度振幅。計算tl時，空氣濾清器的出口部分給出了

7、單元速度振幅模型的聲源，所有 其他的表面被建模為“聲學(xué)硬”默認(rèn)情況。出口部分的聲功率可以從公式計算。 所有后續(xù)的tl的預(yù)測具有相同的邊界條件。預(yù)測的空氣濾清器性能。在發(fā)動機(jī)進(jìn)氣道的聲功率級是顯示圖的噪聲源信號 峰值為173赫茲的頻率諧波相關(guān)的發(fā)動機(jī)點(diǎn)火。由于發(fā)動機(jī)燃燒分布式低頻率從 100赫茲到800赫茲之間的聲音能量堆積太高， 傳輸損耗在220赫茲到1千赫茲 的頻率范圍內(nèi)是如此之低，噪聲排放不能最小化，所以一個沉默的空氣濾清器具 有較高的tl 200赫茲到1千赫茲的要求。2.2 無聲空氣濾清器的初步設(shè)計如果有足夠的空間，一個復(fù)雜的結(jié)構(gòu)，可以被分配到降低進(jìn)氣噪聲排放。因此我們必須充分利用有限的

8、空間。在這項(xiàng)工作中用cad軟件或pro/e進(jìn)行包絡(luò)發(fā)動機(jī)室中的其他汽車部件的剩余空間。 然后從籠罩空間獲得的總體積所需的空 氣濾清器。下一步是選擇合適的消聲器單元和它們的尺寸。考慮空氣凈化效果， 必須滿足兩個要求：（1）空氣流量應(yīng)等于或超過原通量值；（2）過濾面積不能降 解。在這要求的基礎(chǔ)上，對消聲器單元理論初步確定開采布局。 空氣濾清器是由 兩塊隔板分隔成三個膨脹室，右擋板的中間有個洞，左擋板有四個孔的四角，濾 紙放在中間膨脹室的中心。因?yàn)檫@空氣濾清器的復(fù)雜性，孔的直徑大于原來的。 第二個要求是在第一擋板孔的直徑和長度的二室，讓過濾面積等于原來的，然后第二膨脹室的長度可以確定。所以空氣濾清器

9、的幾何結(jié)構(gòu)是由兩個變量確定的。整體的聲學(xué)行為是三室的所有組成元件的行為總和。為了提供連續(xù)衰減譜寬 的帶寬，在他們個人的貢獻(xiàn)衰減最小不應(yīng)同時發(fā)生。為了調(diào)查三室個人的聲學(xué)性 能，綜合空氣濾清器被分成三個部分， 其中之一是擴(kuò)張室消聲器單元，只是在兩 擋板的位置。邊界元法的運(yùn)行進(jìn)行計算的三個個體的聲學(xué)性能。第一室具有高和 連續(xù)在300-1000赫茲頻段的衰減，并在 400-800赫茲的頻率范圍的第二腔室具 有高衰減的聲學(xué)性能稍微比第一個更糟。 第三室性能最差，但在約230赫茲的頻 率，其中第一和第二室的最小衰減，它具有更高的衰減，從而為第一和第二部分 提供的補(bǔ)償效果。同時，在更高的頻率，第三部分可能是

10、良好的聲學(xué)性能，這是 在這個圖中沒有說明。請注意，這種單一的部分還介紹了之間存在不確定性， 聲 相互作用，即使他們的個人表現(xiàn)，可以適當(dāng)?shù)卮砘蚪?。明確的單一部分的聲 學(xué)性能的初始設(shè)計提供了重要的信息。在某些領(lǐng)域的變化，集成系統(tǒng)在獲得最佳 的聲學(xué)性能的詳細(xì)設(shè)計的邊界元法計算。在最初的設(shè)計，外部幾何尺寸已確定，并且已用粗糙的尺寸單位選擇消聲器。 在擋板的位置和四個孔的第二隔板半徑可以改變，以達(dá)到更好的聲學(xué)性能。2.3 噪聲排放預(yù)測直到現(xiàn)在，我們已經(jīng)完成了總體設(shè)計的無聲空氣濾清器。為了與原來的做一個比較，的噪聲輻射進(jìn)行了預(yù)測。為了驗(yàn)證設(shè)計的空氣濾清器的實(shí)用性能，在5200轉(zhuǎn)/分鐘在發(fā)動機(jī)試驗(yàn)臺作

11、為原始和重新設(shè)計的空氣濾清器邊界條件或噪聲源在全油門和發(fā)動機(jī)轉(zhuǎn)速的測量是在發(fā)動機(jī)進(jìn)氣道的聲壓，進(jìn)而預(yù)測噪聲排放進(jìn)空氣濾清器。測量聲壓時，空氣濾清器和發(fā)動機(jī)的噪音屏蔽掉。止匕外，由于在發(fā)動機(jī)的進(jìn) 氣端口測量壓力引起的噪聲信號的空氣流的影響和誘導(dǎo)麥克風(fēng)干擾， 惡化的發(fā)動 機(jī)性能的困難，麥克風(fēng)的測量定位在200毫米到進(jìn)氣端口。邊界條件施加在空氣 濾清器系統(tǒng)出口處應(yīng)在測量位置上面提到的基于聲學(xué)理論從噪聲信號中提取的。在進(jìn)氣道軸的點(diǎn)p的聲壓與最高的相比，在相同的距離其他點(diǎn)的入口段中 心。2.4 盡量減少額外聲功率的方法在使用以前的布局的一個潛在的問題是在 173赫茲的聲音從空氣濾清器的 進(jìn)氣發(fā)射功率水平

12、，頻率不為其他頻段的低。空置面積在管道連接空氣濾清器與 發(fā)動機(jī)的進(jìn)氣口表明其他一些可能的空氣清潔系統(tǒng)的改進(jìn)。 本文采用旁路管來實(shí) 現(xiàn)這一目標(biāo)。提高tl在大約173赫茲的頻率為目標(biāo)確定尺寸 ld = 980毫米。比較預(yù)測 的聲學(xué)性能上的布局與管和柔性分流管的布局現(xiàn)狀沒有改變。 旁路管道布置的聲 學(xué)性能顯著提高在大約173赫茲的頻率和519赫茲的頻率的三倍，大致對應(yīng)半波 長，預(yù)計旁路管道布置tl輕度上升?？梢钥闯觯瑹o輔助空氣凈化器在173赫茲是最高的聲功率級，而旁路管空氣 凈化器在這個頻率大大降低?？偮暪β仕綇?到1千赫，為無旁路管空氣清潔 器110.2分貝，并為旁路管空氣清潔器105分貝。請注

13、意，引擎聲功率級不從實(shí)驗(yàn)檢測進(jìn)氣系統(tǒng)噪聲112.2分貝和無聲的旁通管的空氣清潔器105分貝，所以重新設(shè)計的無聲空氣濾清器切實(shí)降低發(fā)動機(jī)整體 噪聲為最小的進(jìn)氣系統(tǒng)噪聲。3結(jié)論本文報道了一個邊界元法的輔助設(shè)計無聲空氣濾清器。在最初的設(shè)計中，基 于聲學(xué)理論和要求并考慮空間約束，進(jìn)行空氣濾清器總體積、空氣濾清器的粗糙 的內(nèi)部尺寸的測定。之后，一個有效的方法應(yīng)用到173赫茲的頻率的聲學(xué)性能的 改善。邊界元法的聲學(xué)工程設(shè)計使用幫助迅速增加。本文的研究結(jié)果為無聲空氣濾 消器的工程應(yīng)用指南。流量的影響在本研究中并沒有考慮。雖然平均流將不會對聲學(xué)性能影響顯著，這可能對空氣凈化性能的影響和濾紙的影響被忽略， 盡管

14、它可能會影響在高 頻率的空氣濾清器聲學(xué)性能。未來的研究應(yīng)包括在高頻率上的空氣凈化和過濾紙 上的聲學(xué)性能影響的流動的影響。6參考文獻(xiàn)1 bilawchuk, s., fyfe, k.r., 2003. comparison and implementation of the various numerical methods used for calculating transmission loss in silencer systemsj. applied acoustics, 64:903-916.2 davies, p.o.a.l., 1996. piston engine intake

15、 and exhaust system designj. journal of sound and vibration,190:677-712.3 wu, t.w., cheng, c.y .r., tao, z., 2003. boundary element analysis of packed silencers with protective cloth and embedded thin surfacesj. journal of sound and vibration,261:1-15.一個用于內(nèi)燃發(fā)動機(jī)進(jìn)氣系統(tǒng)的無聲空氣濾清器的虛擬設(shè)計及性能預(yù)測virtual design an

16、d performance prediction of a silencing aircleaner used in an i.c. engine intake systemhao zhi-yong, jia wei-xin, fang fang(college of mechanical and energy engineering, zhejiang university, hangzhou 310027, china) (tianjin internal combustion engine research institute, tianjin university, tianjin 3

17、00072,china)e-mail: ; received jan. 17, 2005; revision accepted may 12, 2005abstract： this paper reports results of the authors studies on the virtual design method used in the development of low noise intake system of i.c. engine. the resulting high pass-by noise at le

18、vel above the legislative target at full throttle when engine speed was around 5200 r/min necessitated a bem-aided redesign task, following the typical process of design and development of an intake system. during the initial design, based on the acoustic theory and the requirements and considering

19、the constraint of space in the engine compartment, total volume and rough internal dimensions were determined. during the detailed design, the exact internal dimensions of the air cleaner were determined, and an effective method was applied to improve the acoustic performance at low frequency. the p

20、redicted sound power of the intake system indicated that the objective of reducing the overall engine noise by minimizing intake system noise was achieved.key words: virtual design; acoustic performance; silencing air cleaner; boundary element method (bem)introductionthe primary function of an the p

21、rimary function of an intake system is firstly to efficiently channel fresh air to the engine, and secondly to minimize intake noise emissions. there are a number of current approaches for developing a more realistic method to improve intake system design. the objectives include more effective silen

22、cing performance to meet increasingly severe legislative targets for reduced noise on the one hand, with optimized engine performance and fuel economy accompanied by improvements in vehicle quality on the other hand.a typical procedure followed during the design and development of an intake system f

23、or a vehicle engine is shown. the design process includes a careful tuning of all components of theintake system that influence noise emission with optimized matching of these to the engine7一個用于內(nèi)燃發(fā)動機(jī)進(jìn)氣系統(tǒng)的無聲空氣濾清器的虛擬設(shè)計及性能預(yù)測operational and breathing characteristics influencing pollutant emission, perfo

24、rmance and economy. starting with an existing or notational system layout, an integrated assessment of the various performances is performed. this information may then be used appropriately to assess current system performance in terms of the various design objectives, to provide rational basis for

25、systematic optimization of the design by implementing appropriate modifications to its constituent elements.the bem widely used in the design of intake and exhaust system can be used to compute the interior, exterior, or both fields simultaneously and only requires that the perimeter of the air clea

26、ner be divided into elements;and the ease in imposing the boundary condition is another attraction. in this paper bem is used to predict the air cleaners transmission loss and noise emission.the redesign of the original intake system arises in connection with a high pass-by noise with level above th

27、e legislative target at full throttle with engine speed around 5200 r/min. the spectral characteristics of the noise signal are normally dominated by an extensive sequence of discrete tones that are harmonically related to the engine firing frequency which is 173 hz corresponding to 5200 r/min and t

28、he inline 4-cylinder 4-stroke engine. in many instances the bulk of the acoustic energy from the primary source is distributed among the lower frequency components that may be difficult to control. thus frequency range this paper referred to is from 0 to 1 khz. in this frequency range, as the influe

29、nce of filter paper on acoustic performance of integrated system is trivial, so filter paper is disregarded. the noise is emitted from the inlet of the air cleaner, and the outlet of the air cleaner system connects to the inlet of the engine. so the pressure at the inlet of the engine or the outlet

30、of the air cleaner is the boundary condition for the bem.traditional intake system with a function of noise reduction normally has two parts: air cleaner and silencer. due to the constraint of space in the engine compartment, the redesigned air cleaner combines the effect of cleaning and silencing.

31、in this work, a so-called silencing air cleaner was redesigned, with geometrical structure determined by predicted tl and sound power emission by bem. also, in order to minimize the sound power of the intake system at low frequency, a bypass pipe was added to the air-channeling pipe. analysis of the

32、 resulting acoustic performance showed that the method is feasible for the goal of reducing the overall engine noise by minimizing the intake system noise.design of the silencing air cleaneroriginal air cleaner evaluationthis original air cleaner of mainly cleaning design paying little attention to

33、minimizing noise emission is its bem mesh.during calculation of tl, the outlet section of the air cleaner is given a unit velocity amplitude to model a sound source, all other surfaces are modeled as acoustically hard by default . the sound power of the outlet section can be calculated from the form

34、ula. all the subsequent tl predictions have the same boundary condition.the predicted air cleaner performance is shown the sound power level at the engine intake port is shown . the peaks of the noise source signal are harmonically related to the engine firing frequency of 173 hz. as the bulk of the

35、 acoustic energy from the engine combustion distributed among the low frequencies from 100 hz to 800 hz is too high, the transmission loss at the frequency range of 220 hz to 1 khz is so low that the noise emission cannot be minimized, so a silencing air cleaner with a higher tl at 200 hz to 1 khz i

36、s required.initial design of the silencing air cleanerif there is sufficient space, a complex structure can be assigned to minimize the intake noise emission. so we must make good use of the limited space. in this work cad software pro/e was used to envelop the rest of the space of the other automot

37、ive components in the engine compartment. then the total air cleaner volume required is obtained from the enveloped space. the next step is to choose appropriate silencer units and their dimensions. considering the effect of air cleaning, two requirements must be satisfied: (1) the air flux should e

38、qual to or exceed the value of original flux; (2) the filtering area must not be degraded. based on the requirements and the theory of the silencer units, an initial layout was deter- mined. the air cleaner is separated into three expansion chambers by two baffles, the right baffle has a hole in the

39、 middle, and the left baffle has four holes at its four comers respectively. the filter paper is placed at the center of the middle expansion chamber. the diameter of the hole in the right baffle is determined by the first requirement; because of the complexity of this air cleaner, the diameter of t

40、he hole is bigger than the original one. the second requirement relates to the diameter of the hole in the first baffle and the length of the second chamber, after letting the filtering area be equal to the original one, thenthe length of the second expansion chamber can be determined. so the geomet

41、rical structure of the air cleaner is set by two variables.the overall acoustic behavior is a summation of the behavior of all constituent components of the three chambers. in order to provide a wide bandwidth of continuous attenuation spectrum, the attenuation minimum in their individual contributi

42、ons should not occur simultaneously. in order to investigate the individual acoustic performance of the three chambers, the integrated air cleaner was separated into three parts, one of which is a silencer unit of expansion chamber, just at the place of the two baffles. bem run was performed to calc

43、ulate the individual acoustic performance of the three chambers. the first chamber has high and continuous attenuation at the frequency band of 300-1000 hz, and the acoustic performance of the second chamber which has high attenuation at the frequency range of 400-800 hz is a shade worse than that o

44、f the first one. the third chamber has the worst performance, but at the frequency of about 230 hz, where the first and the second chamber have minimal attenuation, it has higher attenuation, thus providing compensation effect for the first and second parts. also, at higher frequency, the third part

45、 possibly represents good acoustic performance, which is not illustrated in this figure.note that the acoustic interactions that exist between such single parts also introduced uncertainties, even when their individual performance can be appropriately represented or modeled. clear understanding of t

46、he acoustic performance of the single part gives significant information for initial design . the integrated system with changes in some areas is calculated by the method of bem in the detailed design to gain the best acoustic performance.in the initial design, the external geometrical dimension is

47、decided, and silencer unit with a rough dimension is chosen. while the position of the baffles and the radius of the four holes in the second baffle can be varied to achieve better acoustic performance.noise emission predictionuntil now, we have accomplished total design of the silencing air cleaner

48、. in order to make a comparison with the original, prediction of the noise emission was carried out.to verify the practical performance of the redesigned air cleaner, the sound pressure at the engine intake port was measured at full throttle with engine speeds at 5200 r/min at engine test bed as the

49、 boundary condition or noise source of the original and the redesigned air cleaner, then predicting the noise emission from the inlet of the air cleaner.when measuring this sound pressure, the air cleaner was removed, and the engine noise was shielded off. in addition, due to the difficulties in mea

50、suring the pressure at the engine intake port be- cause of the air flow influence on noise signals and the induced microphone disturbance that deteriorate the engine performance, the measurement location of the microphone was at the place 200 mm to the intake port, and at 45 to the normal of the int

51、ake port section . the boundary condition applied at the outlet of the air cleaner system should be extracted from the noise signals at the measurement location mentioned above based on acoustic theory.the sound pressure of the point p0 at the axis of the intake port is the maximum compared to the o

52、ther points with the same distance to the center of the intake port section o.extra method to minimize sound powerone potential problem in using the previous layout is that at the frequency of 173 hz the level of sound power emitted from air cleaners inlet is not as low as that of other frequency ba

53、nds. the vacant space around the pipe connecting the air cleaner and the engine intake port suggests some other possible improvements of the air cleaner system. this paper uses a bypass pipe to achieve this goal.increasing of tl at frequency of around 173 hz being the goal determines that dimension

54、ld=980 mm. compare the predicted acoustic performance between the previous layout with no change on pipe and the present layout with flexible bypass pipe. the acoustic performance of the bypass pipe layout improved dramatically at frequency of around 173 hz, and at frequency of 519 hz, corresponding

55、 roughly to thrice of half wavelength, the tl of bypass pipe layout increased lightly, as expected.the resulting sound power level is illustrated . it can be seen that sound power level of the without-accessory air cleaner at 173 hz is the highest, while that of the with-bypass-pipe air cleaner at this frequency is greatly decreased. the overall sound power level from 0 to 1 khz, for the without-bypass-pipe air cleaner is 110.2 db, and for the with-bypass-pipe air cleaner is 105.