This work presents the results of an intensity-based fuel–air calibration for a range of charge pressures for gasoline fuel. The radical intensity ratio of diatomic carbon (C₂^*) to methylidene (CH*) was acquired through line-of-sight chemiluminescence imaging at pressures up to 10 bar. Certified gasoline (99% iso-octane, 0.9% n-heptane, and 0.1% other additives) and air are injected into an optically accessible pressure vessel capable of handling pressures up to 200 bar and ignited with an automotive spark plug. Line-of-sight images of C₂^* and CH* are recorded simultaneously on a single image sensor utilizing an intensifier, a high-speed camera, and various optical components to split the light signals associated with C₂^* and CH* (centered at 513 and 427 nm, respectively). The ratio of the signals (C₂^*/CH*) are acquired and compared to the measured equivalence ratio of the exhaust gases and charge pressure. The approach allowed for characterization of the behavior of the intensity ratio at various charge pressures for gasoline. The comparison of the intensity ratio (C₂^*/CH*), equivalence ratio, and charge pressure resulted in the generation of a correlation map that can be used to calculate equivalence ratio if intensity ratio and charge pressure are known.

中文翻译：

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C ₂ *和CH *的化学发光强度比，充气压力和汽油当量比之间的关系

这项工作展示了针对汽油充气压力范围进行基于强度的燃油-空气校准的结果。通过在高达10 bar的压力下通过视线化学发光成像获得双原子碳（C ₂ ^*）与亚甲基（CH *）的自由基强度比。将经过认证的汽油（99％的异辛烷，0.9％的正庚烷和0.1％的其他添加剂）和空气注入能够处理高达200 bar压力的光学可访问压力容器中，并用汽车火花塞点火。使用增强器，高速相机和各种光学组件将C ₂ ^*和CH *的视线图像同时记录在单个图像传感器上，以分离与C ₂相关的光信号^*和CH *（分别位于513和427 nm的中心）。获取信号的比率（C ₂ ^* / CH *），并将其与测量的废气和增压压力的当量比率进行比较。该方法允许表征在各种充气压力下汽油的强度比的行为。强度比（C ₂ ^* / CH *），当量比和充气压力的比较导致了相关图的生成，如果已知强度比和充气压力，则可以使用该相关图来计算当量比。