Cycle-resolved measurements of the fuel concentration near a spark plug in a rotary engine using an in situ laser absorption method
Cycle-resolved measurements of the fuel concentration near a spark plug in a rotary engine using an in situ laser absorption method
复制标题
DOI：
10.1016/j.proci.2006.08.088
复制
发表时间：
2007
期刊：
影响因子：
--
通讯作者：
N. Kawahara;E. Tomita;Kenta Hayashi;M. Tabata;Kouhei Iwai;Ryoji Kagawa
中科院分区：
文献类型：
--
作者：
N. Kawahara;E. Tomita;Kenta Hayashi;M. Tabata;Kouhei Iwai;Ryoji Kagawa
对某商用旋转式发动机火花塞附近的燃料浓度进行了循环分辨测量。利用火花塞传感器和3.392μ的He-Ne激光作为光源，建立了一种原位激光红外吸收方法。该波长与碳氢化合物的吸收线相吻合。由于石英透镜和两根光纤的优化，新开发的红外火花塞传感器比以前的版本具有更高的信噪比。新的传感器提供了高时间分辨率的火花塞周围循环分辨燃料浓度的定量测量。在预置的稀薄空气/燃料(A/F)比下，燃料通过转子在旋转式发动机塞孔中的运动逐渐与周围的空气混合。在压缩行程中测量到了强烈的混合物不均匀性；在整个压缩行程中，这些不均匀性的大小有所降低。通过循环分辨测量，研究了火花塞附近燃料浓度对商用旋转式发动机燃烧特性的影响。在初始燃烧阶段，火花塞传感器测量的燃料浓度与燃烧特性之间存在很强的相关性，当条件比火花塞附近的化学计量比稍丰富时，燃烧特性发生得更快。指示平均有效压力(IMEP)与火花塞附近的空燃比关系不大。使用最新开发的火花塞传感器，可以测量火花塞附近循环分辨的空燃比，并研究其周期间的波动，以实现稳定运行。
Cycle-resolved measurements of the fuel concentration near a spark plug in a commercial rotary engine were performed. An in situ laser infrared (IR) absorption method was developed using a spark plug sensor and a 3.392-μm He–Ne laser as the light source. This wavelength coincided with the absorption line of hydrocarbons. The newly developed IR spark plug sensor had a higher signal-to-noise ratio than its previous version due to the optimization of its quartz lens and two optical fibers. The new sensor provided quantitative cycle-resolved fuel concentration measurements around the spark plug with a high temporal resolution. At lean preset air/fuel (A/F) ratios, fuel was mixed with the surrounding air gradually by the rotor motion in the plug hole of the rotary engine. Strong mixture inhomogeneities were measured during the compression stroke; the magnitude of these inhomogeneities decreased throughout the compression stroke. Cycle-resolved measurements were made to investigate the effects of the fuel concentration near the spark plug on the combustion characteristics of the commercial rotary engine. There was a strong correlation between the fuel concentration measured with the spark plug sensor and the combustion characteristics during the initial combustion period, which occurred faster when conditions were slightly richer than stoichiometric near the spark plug. The indicated mean effective pressure (IMEP) was slightly related to the A/F ratio near the spark plug. It was possible to measure the cycle-resolved A/F ratio near the spark plug and investigate its cycle-to-cycle fluctuations to achieve stable operation using the newly developed spark plug sensor.