Question

急求汽车专业英语翻译

Excess-air factor
The designation l (lambda) has been selected to identify the excess-air factor (or air ratio) used to quantify the spread
between the actual current mass A/F ratio and the theoretical optimum (14.7:1):
l = Ratio of induction air mass to air requirement for stoichiometric combustion.
l = 1: The inducted air mass corresponds to the theoretical requirement.
l < 1: Indicates an air deficiency, producing a corresponding rich mixture.Maximum power is derived from l =0.85...0.95.
l > 1: This range is characterized by excess air and lean mixture, leading to lower fuel consumption and reduced
power. The potential maximum value for l–called the “lean-burn limit (LML)”–is essentially defined by the design of the
engine and of its mixture formation/induction system. Beyond the
lean-burn limit the mixture ceases to be ignitable and combustion miss sets in,accompanied by substantial degeneration
of operating smoothness.In engines featuring systems to inject fuel directly into the chamber, these operate with substantially higher excess-air factors (extending to l = 4) since combustion
proceeds according to different laws.
Spark-ignition engines with manifold injection produce maximum power at air deficiencies of 5...15 % (l = 0.95...0.85),but maximum fuel economy comes in at 10...20% excess air (l = 1.1...1.2).Figures 1 and 2 illustrate the effect of the
excess-air factor on power, specific fuel consumption and generation of toxic emissions. As can be seen, there is no
single excess-air factor which can simultaneously generate the most favorable levels for all three factors. Air factors of l = 0.9...1.1 produce “conditionally optimal” fuel economy with
“conditionally optimal” power generation in actual practice.
Once the engine warms to its normal operating temperature, precise and consistent maintenance of l = 1 is vital for the 3-way catalytic treatment of exhaust gases. Satisfying this requirement entails exact monitoring of induction-air mass and precise metering of fuel mass.Optimal combustion from current engines equipped with manifold injection relies on formation of a homogenous mixture as well as precise metering of the
injected fuel quantity. This makes effective atomization essential. Failure to satisfy this requirement will foster the
formation of large droplets of condensed fuel on the walls of the intake tract and in the combustion chamber. These droplets
will fail to combust completely and the ultimate result will be higher HC emissions.

Answer 1

过度-空气的因素
指示 l(Lambda) 已经被选择识别过度-空气的因素 (或者空气比) 过去一直定量那传布
在真实的现在大众的 A/F 比和理论上的最适宜 (14.7:1) 之间:
归纳法气团的 l= Ratio 晾干制的 stoichiometric 燃烧的需求。
l=1: 被引导的气团符合理论上的需求。
l<1: 指出空气缺乏,产生一个对应的富有混合汽。最大动力起源于 l=0.85.。..
l>1: 这一范围有过度空气和稀混合汽的特点, 带领降低燃料消耗量而且减少
电力。 潜在的最大价值为 l-呼叫 " 瘦肉-烧伤的界限 (LML)"-本质上被设计定义那
引擎和它的混合汽形成/归纳法制度。 超过那
瘦肉-烧伤的界限混合汽停止是易起火的，而且燃烧过错开始 ,被可观退化陪伴
操作柔滑。在以系统为特色进入室之内直接地注射燃料的引擎中, 自从燃烧以后这些和实质上比较高的过度-空气的因素 (对 l 扩充 =4) 操作
依照不同的法律收入。
火花-点火的引擎用多种的注入在 5 空气缺乏生产最大动力。。.%(l=0.95.。.),但是最大值燃料经济在 10 点进来.。.% 过度晾干制的 (l=1.1.。.).图 1 和 2 举例说明效果那
在电力、特性燃料消耗量和有毒散发的世代的过度-空气的因素。 美国标准能被见到, 没有
能同时地产生所有的三个因素的最有利的水平的单一过度-空气的因素。 晾干制的 l 的因素 =0.9.。. 生产 " 有条件最佳 " 燃料经济与
在真实的练习中的 " 有条件最佳 " 发电装置。
一经引擎对它的正常操作温度温暖, l 的精确和一致维护 =1 对废气的 3 方法接触反应治疗是重要的。 满意的这一个需求需要归纳法的精确监听-气团和燃料块的精确的以计量器计量。来自被装备多种的注入的现在的引擎的最佳的燃烧仰赖一个同种的混合汽和精确的以计量器计量的形成那
注射了燃料量。 这使有效的喷雾器必要。 使这一个需求满意的失败将会养育那
浓缩燃料对摄取广阔的地面的墙壁的大小滴的形成和在燃烧室中。 这些小滴
将会无法完全地消耗，而且终极的结果将会是较高的 HC 散发。