125中英文雙語(yǔ)畢業(yè)設(shè)計(jì)外文文獻(xiàn)翻譯成品 在空調(diào)室內(nèi)進(jìn)行氣流分析

1、<p>　　此文檔是畢業(yè)設(shè)計(jì)外文翻譯成品（ 含英文原文+中文翻譯），無(wú)需調(diào)整復(fù)雜的格式！下載之后直接可用，方便快捷！本文價(jià)格不貴,也就幾十塊錢！一輩子也就一次的事！</p><p>　　外文標(biāo)題：Air?ow analysis in an air conditioning room</p><p>　　外文作者：Ooi Yongson, Irfan Anjum Badruddin

2、, , Z.A. Zainal, P.A. Aswatha Narayana</p><p>　　文獻(xiàn)出處:Ooi Yongson, Irfan Anjum Badruddin,et al.Air?ow analysis in an air conditioning room[J].Building and Environment.2007. 42:1531–1537</p><p>　　

3、英文3423單詞，中文5124漢字。</p><p>　　Air?ow analysis in an air conditioning room</p><p>　　Ooi Yongson, Irfan Anjum Badruddin, , Z.A. Zainal, P.A. Aswatha Narayana</p><p>　　Abstract:The aim o

4、f superior air conditioning system is no longer constrained to advancing the efficiency of cooling machine, but includes the study of air?ow with the assistance of the distribution of several significant parameters. A si

5、mple numerical study of the turbulent ?ow over an enclosed air conditioning system was not practicable a few decades ago since the computer facilities were not sufficient. In this paper, a standard of?ce room was taken u

6、p for simulation. Temperature and velocity</p><p>　　1.Introduction</p><p>　　As the standard of living is increasing, more and more people are seeking for a comfortable living whether in work or

7、at rest. Air conditioner has become a popular comfort- providing device since two decades. It has become a need for everyone, whether in an of?ce or home especially for warm and wet climate countries like Malaysia. Peopl

8、e are seeking for more comfortable working environment in order to perform their duties well. Main objective of an air conditioning system, in general, is to prov</p><p>　　experimental work. This tool is cap

9、able for analyzing the ?ow pattern of the air conditioning system in short span of time, which was previously impossible from experimental and theoretical methods [2]. Moreover, CFD gives virtual distribution of air?ow,

10、temperature, etc. in entire domain which is highly dif?cult to get from experiments because of time and cost involved. Unfortunately, there is no universal ?ow model to represent the entire ?ow pattern for the air condit

11、ioning system [3].</p><p>　　Recently, research has been carried out in relation to air?ow in an air conditioning room. Heating, ventilating and air conditioning (HVAC) have been analyzed by Mathews et al. [4

12、] for the use of human science building (HSB) at the University of Pretoria wherein there is a saving of 60% in power consumption. Besides, indoor humidity behaviors associated with decoupled cooling in hot and humid cli

13、mates have been analyzed by Zhang and Niu [5]. Cheong et al. [6] have carried out a research on the d</p><p>　　2.Modeling</p><p>　　2.1. Interior design</p><p>　　A standard room mode

14、l of a single of?ce room, which contains information of ?oor plans, has been taken from a standard reference book [8]. The width (y-direction); length (x-direction) and height (z-direction) are 2.7; 3.7 and 3.0 m, respec

15、tively, which is shown in Fig. 1(a). Formally there is no ?xed arrangement for the furniture. It will depend on the style and the favorites of the occupant of the room itself. Subsequently, an idea of the furniture arran

16、gement including the placement location </p><p>　　2.2. Blower placement</p><p>　　For a single of?ce room, normally a split unit will be used. There are three most suitable blower placement locat

17、ions, which have been named as locations I, II and III as shown in Fig. 1(b)–(d), respectively.</p><p>　　2.3. Governing equations</p><p>　　There are three groups of basic equations, which are de

18、rived from three basic physics laws of conservation. The mass conservation, momentum conservation and energy conservation results in the continuity equation, Navier–Stokes equation and energy equation, respectively. Sinc

19、e the ?ow in an air conditioning room is turbulent ?ow [10], the k–epsilon and the Reynolds stress viscous models have been chosen for investigation.</p><p>　　The standard k–epsilon model is a semi-empirical

20、 model based on model transport equations for the turbulent kinetic energy (k) and its dissipation rate (e). The transport equation for k is derived from the exact equation, while the transport equation for e is obtained

21、 using physical reasoning and bears little resemblance to its mathematically exact counterpart.</p><p>　　The turbulent kinetic energy, k, and its rate of dissipation, e, are obtained from the following trans

22、port equations:</p><p>　　Fig. 1. The sketch of the room model: (a) coordinate system for the entire room; (b) blower placement in location I; (c) blower placement in location II and (d) blower placement in l

23、ocation III.</p><p>　　Convective heat and mass transfer modeling in the k–epsilon models is given by the following:</p><p>　　Abandoning the isotropic eddy-viscosity hypothesis, the Reynolds stre

24、ss model (RSM) closes the Reynolds-aver- aged Navier–Stokes equations by solving transport equations for the Reynolds stresses, together with an equation for the dissipation rate. This means that four additional transpor

25、t equations are required in two-dimensional flows and seven additional transport equations must be solved in three-dimensional ?ows. Since the RSM accounts for the effects of streamline curvature, swirl, rotatio</p>

26、;<p>　　The exact transport equations for the transport of the Reynolds stresses, r uiuj, may be written as follows:</p><p>　　The turbulent kinetic energy, k, and its rate of dissipation, e, are obtain

27、ed from the following transport equations:</p><p>　　The convective heat and mass transfer modeling in the Reynolds stress models will be same as k–epsilon model, which is given by the following relation:<

28、/p><p>　　To solve these equations, initial and boundary condition must be speci?ed around the boundary of system (domain). Because the equations are highly nonlinear, they are not solvable by explicit, closed-f

29、orm analytical methods. The numerical ?nite volume method as used in Fluent has been used for solving the equations.</p><p>　　The domain is discretized into cells or elements and nodal points are de?ned. Upo

30、n solution of the equations, the values of the dependent variables are known at the nodal points. The values of some constants in the differential equations are given in Table 1. All slandered values have been used for s

31、imulation purpose.</p><p>　　2.4. Boundary conditions</p><p>　　Fig. 2 shows the circulation of air through the blower. Hot air enters surface (ABCD) and cool air ?ows out from the blower at surfa

32、ce (CDEF).</p><p>　　Fig. 2. The air?ow in and out at the blower.</p><p>　　2.5. Grid spacing</p><p>　　There are various types of cells, which can be used for meshing purpose. The ava

33、ilable three-dimensional cell types are tetrahedron, hexahedron, prism as well as pyramid. The hexahedron cell has been chosen due to its homogeneity with the room model. The three types of grid spacing are 15 cm (coarse

34、), 10 cm (medium) and 7.5 cm (?ne). Table 2 shows the number of hexahedron cells with respect to their grid spacing or mesh size.</p><p>　　2.6. Virtual planes</p><p>　　The simulated description

35、will contain parameters such as temperature, velocity, pressure, etc. in every location point in the entire ?ow volume, which is in three dimensions. Present method gives a general picture for the comfort in room. For sw

36、ing attached, the analysis will be complicated and is a function of time. Thus, it is assumed that the air ?ows at 451 from blower. For presenting the results in a simple way, eight planes have been designated which can

37、be in horizontal and vertical dire</p><p>　　2.7. Residual</p><p>　　The accuracy in the CFD simulation is obtained in terms of residual. Residual is the measurement of the error. The smaller the

38、residual, the smaller is the error. Fig. 3 shows the plot of residuals versus number of iterations for model (RSM 10-1) with the Reynolds stress viscous model; grid spacing of 10 cm and the blower location at location I.

39、</p><p>　　While observing the variation of residual with respect to number of iterations, the residual keeps on decreasing from the start to around 800 iterations. Then, the residual remains same although th

40、e numbers of iterations have increased. The iteration has been stopped since there is no variation in the result. This has been applied to all the simulated models.</p><p>　　Results and discussion</p>

41、<p>　　3.1. Comparison of viscous models</p><p>　　There are two types of viscous models to be considered, which are k–epsilon and Reynolds stress model. It is important to make sure that the suitable vi

42、scous model is applied to the model to be simulated. So, a model where the blower is placed in location I is chosen for investigating the variation of temperature over a selective virtual surface, z-top. It is seen from

43、Fig. 4 that all the contours are different from each other except for Figs. 4(e) and (f), which are nearly the same. Therefore, </p><p>　　Fig. 3. Residual plotting for RSM 10-1 model</p><p>　　Th

44、e computational time also is another factor to be considered while dealing with the long time simulation. The simulation times for all models are shown in Table 4. Even though simulation time for Reynolds stress models i

45、s nearly twice simulation time of k–epsilon models, Reynolds stress model is chosen for further analysis, as it is grid independent. The computational time of Reynolds stress model for grid spacing 7.5 cm (10.0 h) is 4.5

46、 times more than the spacing of 10 cm (2.2 h). There is no</p><p>　　3.2. Suitable blower placement location</p><p>　　To observe the suitable position of blower placement, analysis of eight virtu

47、al planes has been carried out for locations I, II and III. Among the planes, the z-center plane</p><p>　　is the most important plane since it represents the condition of the room well. The suitable blower l

48、ocation also can be found out by investigating the various parameter distributions over the various planes. Para- meters like velocity magnitude and temperature have been analyzed as done by Ladeinde and Nearon [11]. Amo

49、ng the planes that have been studied, z-center is the best plane to view the temperature as well as velocity magnitude distribution in horizontal direction near the occupant. It i</p><p>　　Fig. 4. Comparison

50、 between k–epsilon and Reynolds stress for temperature distribution at speci?ed z–top plane with grid spacing. All values are in degree Kelvin.</p><p>　　By observing the velocity magnitude over various plane

51、s for blower placement in locations I, II and III, as in Fig. 5 the air velocity around the occupant and table are in the range of 0.4–1.5 m/s (highlighted with dotted outline square in indicator bar). This is the criter

52、ion for ‘weak wind’, which is the most comfortable velocity magnitude to the occupant. The distribution of velocity magnitude over the entire z-center plane for locations I, II and III are shown in Fig. 5(a)–(c), respect

53、ively.</p><p>　　Fig. 5. Velocity magnitude distribution over a virtual surface z-center for blower: (a) location I; (b) location II and (c) location III. All values are in meter per second.</p><p&

54、gt;　　Fig. 6. Three-dimensional view of velocity vectors for three horizontal plane perpendicular to z-axis.</p><p>　　The directions of the air?ow slowly change to horizontal component while moving further aw

55、ay from the occupant. The magnitude of the air velocity is high on the top plane and getting reduced when it ?ows downward to the occupant as shown in Fig. 6.</p><p>　　Components of vectors are also plotted

56、on the most critical center plane, when air is passing through the body of the occupant (Fig. 7). The components vectors are small in magnitude close to the occupant, whereas the vector magnitude increases while getting

57、further away from the occupant. It can be seen from this ?gure that the occupant area is a comfortable zone to sit since smaller vector magnitude are desirable to avoid disturbance due to wind. As shown in Fig. 7, the ai

58、r is ?owing back to t</p><p>　　Fig. 7. Velocity vectors when air passing through occupant (plane at centre of z-axis).</p><p>　　Fig. 8. Temperature distribution over a virtual surface z-center f

59、or blower: (a) location I; (b) location II and (c) location III. All values are in degree Kelvin.</p><p>　　For temperature criteria, the temperature for comfort should be in the range of 20–25 1C. All the th

60、ree-blower placement locations ful?ll this criterion. But to reduce the size of compressor, it seems to choose a location that will provide the coolest region near the occupant. It saves cost with smaller compressor and

61、consumes lower power, at the same time provides comfort to the occupant.</p><p>　　If the blower is placed in location I, the temperature is distributed more or less uniformly over the entire room as shown in

62、 Fig. 8(a), but the occupant is not sitting in the coolest region of the entire room. So, a better position of the blower should be found since this is not the best position. By referring to Fig. 8(b) where the blower is

63、 placed in location II, although the temperature is not uniformly distributed over the entire room, but it satis?es the requirement of air conditioning of?</p><p>　　Next, the location III is analyzed. The oc

64、cupant is sitting in the hottest region of the entire room as shown in the Fig. 8(c). So, this location is totally not effective and is the worst among the three possible locations that have been discussed.</p>&l

65、t;p>　　Since this is a three-dimensional case, the temperature distributions for other virtual planes have also been investigated. It is observed that placement in location II will provide the maximum comfort for the o

66、ccupant or in other words, occupant experience the coolest temperature when the blower is located in location II. Hence, location II will be the suitable location for the blower placement.</p><p>　　3.3. Comf

67、ort region</p><p>　　Previously, the furniture arrangement is ?xed and the problem is to ?nd the suitable blower placement location. Now is the other way around. The same models stated in previous sections ar

68、e used to locate the comfort region or coolest region for energy saving as stated before. As shown in the plan view in Fig. 6, the dotted outline square covers the cool region (contours are blue in color) for the entire

69、room for three possible blower placement locations. This is applicable to help the furniture </p><p>　　While the blower is placed in location I, almost the entire room is in blue color contours. It is seen t

70、hat almost the whole area has cool condition while the occupant can be located center left by referring to Fig. 8(a). This will be the suitable location when this room is used for living room or multiple functional hall

71、while there is a need to cool the entire room. For location II, the cool region is smaller compared to the location I. The cool air is just concentrated at the left side of the</p><p>　　4.Conclusion</p>

72、;<p>　　1.Between Reynolds stress model and k–epsilon model, Reynolds stress model seem to be grid independent than k–epsilon model for the three-grid spacing investigated. Although simulation of Reynolds stress mo

73、del takes a longer time compared to the k–epsilon model, but mesh spacing independency seem to be more signi?cant.</p><p>　　2.Location II is found to be the most suitable location to place the air conditione

74、r blower. The temperature distribution shows that the occupant is seated in the cool region.</p><p>　　3.The occupant will experience most cool region if the air conditioner blower is placed on location II co

75、mpared to the other two locations.</p><p>　　4.This work can also be extended to a more complex air conditioning system like in the industries, hospitals as well as the gigantic shopping malls.</p><

76、;p>　　References</p><p>　　[1] Haines RW. Control system for heating, ventilating and air conditioning. 2nd ed. New York: Van Nostrand Reinhold; 1977.</p><p>　　[2] Anderson JD. Computational ?u

77、id dynamics. International Edition.New York: McGraw-Hill; 1995.</p><p>　　[3] Baker AJ, Richard MK, Eliott BG, Subrata Roy, Edward GS. Computational ?uid dynamics: a two-edged sword. ASHRAE Journal 1997:51–8.

78、</p><p>　　[4] Mathews EH, Botha CP, Malan A. HVAC control strategies to enhance comfort and minimise energy usage. Energy and Buildings 2001;33:853–63.</p><p>　　[5] Zhang LZ, Niu JL. Indoor humi

79、dity behaviors associated with decoupled cooling in hot and humid climates. Building and Environment 2003;38:99–107.</p><p>　　[6] Cheong KWD, Djunaedy E, Poh TK, Tham KW, Sekhar SC, Wong NH, et al. Measureme

80、nts and computations contaminant’s distribution in an of?ce room. Building and Environment 2003;38:135–45.</p><p>　　[7] Sekhar SC, Ching CS. Indoor air quality and thermal comfort studies of an under-?oor ai

81、r-conditioning system in the tropics. Energy and Buildings 2002;34:431–44.</p><p>　　[8] Jerold LA. Architectural plan for adding on or remodeling. TAB Books; 1992.</p><p>　　[9] Wong J. The moder

82、n design for living. Taiwan: Wanibooks/ Sharppoint; 1995.</p><p>　　[10] Su M, Chen Q, Chiang C-M. Comparison of different subgrid-scale models of large Eddy simulation for indoor air?ow modeling. Journal of

83、Fluids Engineering Transactions of the ASME 2001;123:628–39.</p><p>　　[11] Ladeinde F, Michelle DN. CFD applications in the HVAC & R Industry. ASHRAE Journal 1997;1:44–8.</p><p><b>　　譯

84、文：</b></p><p>　　在空調(diào)室內(nèi)進(jìn)行氣流分析</p><p>　　摘要：優(yōu)越的空調(diào)系統(tǒng)的目標(biāo)不再局限于提高冷卻機(jī)的效率，而是借助于幾個(gè)重要參數(shù)的分布來(lái)研究空氣流動(dòng)。由于計(jì)算機(jī)設(shè)備不足，幾十年前對(duì)封閉式空調(diào)系統(tǒng)的湍流流動(dòng)進(jìn)行簡(jiǎn)單的數(shù)值研究是不可行的。在本文中，一個(gè)標(biāo)準(zhǔn)的文件室被用于模擬。分析了用于空調(diào)鼓風(fēng)機(jī)的不同位置的各種虛擬平面上的溫度和速度分布，以實(shí)現(xiàn)乘員的最大舒

85、適度。使用Fluent作為解決方案工具，使用k-epsilon和雷諾應(yīng)力模型進(jìn)行湍流流動(dòng)分析。分析鼓風(fēng)機(jī)放置的不同位置以使房間中的乘員更舒適，并且發(fā)現(xiàn)如果空調(diào)鼓風(fēng)機(jī)與其他兩個(gè)位置相比放置在位置II上，則乘員將體驗(yàn)到最大的舒適度。這項(xiàng)工作還可以擴(kuò)展到更復(fù)雜的空調(diào)系統(tǒng)，如工業(yè)，醫(yī)院以及巨大的購(gòu)物中心。</p><p><b>　　引言</b></p><p>　　隨著生活

86、水平的提高，越來(lái)越多的人正在尋求舒適的生活，無(wú)論是在工作還是休息。自二十年以來(lái)，空調(diào)已成為一種流行的舒適設(shè)備。它已成為每個(gè)人的需求，無(wú)論是在家中還是家中，特別是對(duì)于像馬來(lái)西亞這樣溫暖潮濕的氣候國(guó)家。為了更好地履行職責(zé)，人們正在尋求更舒適的工作環(huán)境。一般而言，空調(diào)系統(tǒng)的主要目的是為整個(gè)空調(diào)區(qū)域提供最大的舒適度。為了實(shí)現(xiàn)這一目標(biāo)，隨后對(duì)冷卻機(jī)性能的分析將是不充分的。范圍應(yīng)該擴(kuò)大到分析整個(gè)空調(diào)系統(tǒng)的空氣流量[1]。因此，空調(diào)系統(tǒng)的設(shè)計(jì)不再僅僅

87、關(guān)注冷卻機(jī)的有效性。在這個(gè)領(lǐng)域已經(jīng)進(jìn)行了大量的研究。使用計(jì)算流體動(dòng)力學(xué)（CFD）可能不會(huì)完全取代物理實(shí)驗(yàn)，但它可以顯著減少數(shù)量實(shí)驗(yàn)工作。該工具能夠在短時(shí)間內(nèi)分析空調(diào)系統(tǒng)的流動(dòng)模式，這在以前的實(shí)驗(yàn)和理論方法中是不可能的[2]。此外，CFD在整個(gè)區(qū)域中提供空氣流量，溫度等的虛擬分布，由于涉及時(shí)間和成本而非常難以從實(shí)驗(yàn)中獲得。不幸的是，沒(méi)有通用流動(dòng)模型來(lái)代表空調(diào)系統(tǒng)的整個(gè)流動(dòng)模式[3]。</p><p>　　最近，已經(jīng)

88、對(duì)空調(diào)室中的空氣流進(jìn)行了研究。 Mathews等人分析了加熱，通風(fēng)和空調(diào)（HVAC）。 [4]在比勒陀利亞大學(xué)使用人文科學(xué)建筑（HSB），其中節(jié)省了60％的能耗。此外，張和牛[5]分析了與炎熱和潮濕氣候下的解耦冷卻相關(guān)的室內(nèi)濕度行為。 Cheong等。 [6]使用經(jīng)驗(yàn)和建模技術(shù)對(duì)污染物在環(huán)境中的分散進(jìn)行了研究。在虛擬平面內(nèi)的預(yù)定網(wǎng)格點(diǎn)處測(cè)量熱舒適參數(shù)以預(yù)測(cè)供氣噴射的空氣流動(dòng)模式，以及確定Sekhar和Ching [7]中的空間熱膨脹的發(fā)

89、生。在本文中，使用CFD對(duì)單個(gè)房間的空調(diào)系統(tǒng)進(jìn)行了分析。已經(jīng)研究了諸如溫度和速度的各種參數(shù)的分布，以確定空調(diào)鼓風(fēng)機(jī)的最佳放置位置以及適合于乘員的區(qū)域。</p><p><b>　　2.建模</b></p><p><b>　　2.1.室內(nèi)設(shè)計(jì)</b></p><p>　　單個(gè)房間的標(biāo)準(zhǔn)房間模型，包含樓層計(jì)劃的信息，已從標(biāo)準(zhǔn)

90、參考書[8]中獲取。寬度（y方向）;長(zhǎng)度（x方向）和高度（z方向）為2.7;分別為3.7和3.0米，如圖1（a）所示。在形式上，家具沒(méi)有固定的安排。這將取決于房間本身的占用者的風(fēng)格和最愛(ài)。隨后，如圖1（a）所示，在室內(nèi)設(shè)計(jì)的書[9]中給出了包括櫥柜或架子，桌子和椅子的放置位置的家具布置的概念。</p><p><b>　　2.2.鼓風(fēng)機(jī)放置</b></p><p>　

91、　對(duì)于單個(gè)房間，通常使用分體式單元。有三個(gè)最合適的鼓風(fēng)機(jī)放置位置，它們分別被命名為位置I，II和III，如圖1（b） - （d）所示。</p><p><b>　　2.3?？刂品匠淌?lt;/b></p><p>　　有三組基本方程，它們來(lái)自三個(gè)基本的保護(hù)物理定律。質(zhì)量守恒，動(dòng)量守恒和能量守恒分別導(dǎo)致連續(xù)性方程，Navier-Stokes方程和能量方程。由于空調(diào)房間的流動(dòng)是

92、湍流[10]，因此選擇k-epsilon和雷諾應(yīng)力粘性模型進(jìn)行研究。</p><p>　　標(biāo)準(zhǔn)k-epsilon模型是基于湍流動(dòng)能（k）及其耗散率（e）的模型傳輸方程的半經(jīng)驗(yàn)?zāi)Ｐ汀?k的傳輸方程是從精確方程推導(dǎo)出來(lái)的，而e的傳輸方程是用物理推理得到的，與數(shù)學(xué)上精確的對(duì)應(yīng)方幾乎沒(méi)有相似之處。</p><p>　　湍流動(dòng)能k及其耗散率e由以下傳輸方程式得出：:</p><p

93、>　　圖1.房間模型草圖：（a）整個(gè)房間的坐標(biāo)系; （b）位置I的鼓風(fēng)機(jī)放置; （c）位置II的鼓風(fēng)機(jī)放置和（d）位置III的鼓風(fēng)機(jī)放置。</p><p>　　k-epsilon模型中的對(duì)流傳熱和傳質(zhì)建模由以下給出：</p><p>　　放棄各向同性渦粘性假設(shè)，雷諾應(yīng)力模型（RSM）通過(guò)求解雷諾應(yīng)力的傳輸方程以及耗散率的方程來(lái)關(guān)閉雷諾 - 平均Navier-Stokes方程。 這意味

94、著在二維流動(dòng)中需要四個(gè)額外的傳輸方程，并且必須在三維流動(dòng)中求解七個(gè)額外的傳輸方程。 由于RSM以比單方程和雙方程模型更嚴(yán)格的方式解釋了流線曲率，旋渦，旋轉(zhuǎn)和應(yīng)變率的快速變化的影響，因此它更有可能為復(fù)雜的流動(dòng)提供準(zhǔn)確的預(yù)測(cè)。</p><p>　　用于傳輸雷諾應(yīng)力的精確傳輸方程式可以寫成如下:</p><p>　　湍流動(dòng)能k及其耗散率e由以下傳輸方程式得出：:</p><p

95、>　　雷諾應(yīng)力模型中的對(duì)流傳熱傳質(zhì)模型與k-epsilon模型相同，由以下關(guān)系式給出:</p><p>　　要求解這些方程，必須在系統(tǒng)（域）的邊界周圍指定初始和邊界條件。 因?yàn)榉匠淌歉叨确蔷€性的，所以它們不能通過(guò)明確的閉合形式分析方法來(lái)解決。 Fluent中使用的數(shù)值有限體積法已用于求解方程。</p><p>　　域被離散化為單元或元素，并且節(jié)點(diǎn)被定義。 在解方程時(shí)，因變量的值在節(jié)點(diǎn)

96、處是已知的。 微分方程中某些常數(shù)的值在表1中給出。所有的誹謗值都用于模擬目的。</p><p><b>　　2.4. 邊界條件</b></p><p>　　圖2顯示了通過(guò)鼓風(fēng)機(jī)的空氣循環(huán)。 熱空氣進(jìn)入表面（ABCD），冷空氣從表面的鼓風(fēng)機(jī)（CDEF）流出。</p><p>　　圖2.鼓風(fēng)機(jī)進(jìn)出的空氣流量。</p><p>

97、;<b>　　2.5. 網(wǎng)格間距</b></p><p>　　存在各種類型的單元，其可用于網(wǎng)格化目的。 可用的三維細(xì)胞類型是四面體，六面體，棱柱以及金字塔。 由于六面體單元與房間模型的同質(zhì)性，因此選擇了六面體單元。 三種類型的網(wǎng)格間距為15厘米（粗），10厘米（中）和7.5厘米（細(xì)）。 表2顯示了六面體單元的網(wǎng)格間距或網(wǎng)格尺寸的數(shù)量.</p><p><b>

98、;　　2.6.虛擬飛機(jī)</b></p><p>　　模擬描述將包含整個(gè)流體體積中每個(gè)位置點(diǎn)的溫度，速度，壓力等參數(shù)，這些參數(shù)是三維的?，F(xiàn)有方法給出了房間舒適度的一般畫面。對(duì)于擺動(dòng)附件，分析將是復(fù)雜的并且是時(shí)間的函數(shù)。因此，假設(shè)空氣在451處從鼓風(fēng)機(jī)流出。為了以簡(jiǎn)單的方式呈現(xiàn)結(jié)果，已經(jīng)指定了八個(gè)平面，這些平面可以在水平和垂直方向上，以便在整個(gè)體積上清楚地查看信息。表3顯示了已創(chuàng)建的虛擬平面的位置。<

99、;/p><p><b>　　2.7.剩余的</b></p><p>　　CFD模擬的精度是根據(jù)殘差得到的。殘差是對(duì)誤差的測(cè)量。殘差越小，誤差越小。圖3顯示了具有雷諾應(yīng)力粘性模型的模型（RSM 10-1）的殘差與迭代次數(shù)的關(guān)系圖;網(wǎng)格間距為10厘米，位置I處的鼓風(fēng)機(jī)位置。</p><p>　　在觀察殘差相對(duì)于迭代次數(shù)的變化的同時(shí)，殘差繼續(xù)從開(kāi)始減少到

100、大約800次迭代。然后，盡管迭代次數(shù)增加，但殘差保持不變。迭代已經(jīng)停止，因?yàn)榻Y(jié)果沒(méi)有變化。這已應(yīng)用于所有模擬模型。</p><p><b>　　4.結(jié)果和討論</b></p><p>　　3.1.粘性模型的比較</p><p>　　有兩種類型的粘性模型需要考慮，它們是k-epsilon和Reynolds應(yīng)力模型。確保將合適的粘性模型應(yīng)用于要模擬