外文翻譯---基于修正的kantor模型的發(fā)動(dòng)機(jī)循環(huán)變動(dòng)建模

1、<p><b>　　附錄1</b></p><p>　　Modeling of Engine Cyclic Variation by the Modified Kantor Model</p><p>　　Kantor model showing that prior-cycle effects resulting from exhaust gas resi

2、duals are a significant factor in cyclic variability of combustion in IC engines is due to a number of model assumptions that misrepresent the thermodynamic process experienced by the mixture of fresh combustible gas plu

3、s exhaust residual in important ways. In particular we show that exhaust blowdown process and variability exhaust residual gas mass fraction neglected in the Kantor model significantly reduce cyclic vari</p><p

4、>　　Kantor (1984) suggested that cyclic variability can result from a prior-cycle feedback process linked to the temperature of the exhaust residual remaining in the cylinder after the exhaust stroke. The proposed mech

5、anism of feedback is as follows. A slower than average burning process on one cycle will produce a higher exhaust residual temperature since more heat release occurs after part of the expansion process. This leads to a h

6、igher than average intake charge temperature on the following cycl</p><p>　　A. VARIABLE RESIDUAL GAS MASS FRACTION. In the Kantor model the exhaust residual mass fraction is assigned a constant value (0.2

7、), whereas we employ a constant volume fraction, which is a much more realistic and better representation of the actual process in an IC engine because the residuals volume is the same as the combustion chamber volume at

8、 the end of exhaust stroke. With constant volume fraction, cycles with higher/lower exhaust residual temperature will lead to lower/higher residual m</p><p>　　We emphasize that the limitations of the Kantor

9、model are not merely due to simplifications made for analytical convenience, but due to substantive misrepresentations of the thermodynamic process experienced by the mixture of fresh combustible gas plus exhaust residua

10、l. Moreover, none of the modifications we employ here have been considered in the extensions of the Kantor model by Daily (1988) and by Daw and his collaborators (1993). Daily(1998) has examined the effects of activation

11、 energy, com</p><p>　　In the following, the Kantor model and modified Kantor model are described. Then numerical results are obtained and discussed using the Kantor model and the modified model for the reali

12、stic and unrealistic ranges of the model parameters. Finally conclusions are summarized. </p><p><b>　　附錄2</b></p><p>　　基于修正的Kantor模型的發(fā)動(dòng)機(jī)循環(huán)變動(dòng)建模</p><p>　　A. 易變的殘余的氣體大量分?jǐn)?shù)。在

13、Kantor 模型尾氣殘余的許多分?jǐn)?shù)被賦予恒定的價(jià)值(0.2)，但是我們使用一個(gè)恒定的容量分?jǐn)?shù)，是實(shí)際過程一個(gè)更加現(xiàn)實(shí)和更好的表示法。在IC 引擎中因?yàn)闅堄嗳萘康娜紵胰萘堪l(fā)生在排氣沖程的末段。在恒定的容量分?jǐn)?shù)周期中，較高或較低的尾氣殘余的溫度將導(dǎo)致更低或較高的殘余分?jǐn)?shù)，反之將導(dǎo)致廢氣混合物在循環(huán)變化中和空氣混合物在溫度上與Kantor 模型比較產(chǎn)生較小的變化。</p><p>　　B. 膨脹噴射過程。在Kant

14、or 模型尾氣殘余的氣體溫度是在擴(kuò)展沖程的末段。這是非物理的，因?yàn)檫@與氣體等溫膨脹是等效的，與四周壓力沒有溫度的對(duì)應(yīng)。減退膨脹對(duì)四周的壓力必然產(chǎn)生，因?yàn)槲矚鈮毫κ窍蛩闹軘U(kuò)散的。相反，我們假設(shè)，廢氣的部份壓力散失是在氣缸尾氣閥門打開之后，(過程叫“膨脹噴射” 在汽車知識(shí)里)，造成對(duì)它的溫度的減少。我們表示，這個(gè)膨脹噴射過程極大地減輕循環(huán)可變性。這是因?yàn)闊嶙饔没蛟缁蜻t發(fā)生在周期(即在活塞到達(dá)了上止點(diǎn)對(duì)應(yīng)于下止點(diǎn)的圓筒容量)前后，這將導(dǎo)致在燃

15、燒沖程的末端氣體產(chǎn)生一個(gè)更高的溫度，而且燃燒沖程的末段必然導(dǎo)致更高的壓力。在周期燃燒沖程的末段，由于溫度的急劇降低氣體將以更高的壓力擴(kuò)散。</p><p>　　C. 未燒過的燃料。在Kantor 模型中燃燒效率被總體考慮，即所除去排氣氣門開啟之前未燃燒的燃料不考慮外，所有燃燒的燃料都應(yīng)計(jì)算。但從Kantor 提出的慣例作為計(jì)算燃燒曲柄角度的依據(jù)，當(dāng)燃燒角度ATDC 大于 π 時(shí)必須存在某一未燒過的燃料的部份，這導(dǎo)

16、致更低的燃燒效率和在下個(gè)周期增加相等的效率損失比率。根據(jù)Wagner 和 Daw 的工作，我們定義燃燒效率 和整體相等比率 周期為j 的計(jì)算方法如下：</p><p>　　我們強(qiáng)調(diào)， Kantor 模型的局限不僅僅歸結(jié)于為分析便利而作出的簡(jiǎn)化，是由于由新可燃燒的氣體混合物體驗(yàn)加上尾氣殘余產(chǎn)生熱力學(xué)過程的誤差，而且， 我們使用這里的無修改考慮了在Kantor 模型的引伸。Daily 和他的合作者審查了活化作用能量、

17、壓縮比、溫度上升和由于燃燒，燃燒角度、廢氣殘余的分?jǐn)?shù)和灼燒的率前指數(shù)因素的作用的循環(huán)變異。但是，其它引擎操作條件和式樣參量如：相等比率，進(jìn)氣閘壓力等平均參量在實(shí)驗(yàn)中的作用未被考慮。我們看殘余的作用在IMEP（被表明的又意義的有效的壓力）手段和變化是一件更加重要的事，因?yàn)樗緳C(jī)感覺到的唯一參數(shù)為IMEP但不是尾氣溫度。</p><p>　　Kantor 模型和修改過的Kantor 模型被描述。討論使用Kantor 模