The Effect of Knock on the Heat Transfer in an SI Engine: Thermal Boundary Layer Investigation using CARS Temperature Measurements and Heat Flux Measurements
The Effect of Knock on the Heat Transfer in an SI Engine: Thermal Boundary Layer Investigation using CARS Temperature Measurements and Heat Flux Measurements
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爆震对 SI 发动机传热的影响：使用 CARS 温度测量和热通量测量进行热边界层研究
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
P. Bengtsson
中科院分区：
文献类型：
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作者：
B. Grandin;I. Denbratt;J. Bood;C. Brackmann;P. Bengtsson
爆震燃烧对发动机传热的影响是公认的。然而，由于缺乏靠近燃烧室壁面的热边界层的实验数据，传热对爆震发生的影响尚不清楚。本文介绍了在爆震和非爆震条件下热边界层温度的测量。采用双宽带旋转相干反斯托克斯拉曼光谱（CARS）测量温度。同时测量了三个不同位置的气缸压力和壁面的热流密度。通过使用马蹄形燃烧室，在燃烧室的矩形部分安装窗户，可以实现对燃烧室壁面附近区域的光学访问。这种布置使得CARS温度测量接近壁面成为可能，结果显示在距离壁面0.1-5毫米的范围内。发动机在接近化学计量的条件下以恒定的燃油流量运转。通过使用不同的正庚烷和异辛烷的混合物来达到爆震和不爆震的条件。版权所有©2000美国汽车工程师学会（Less）
It is generally accepted that knocking combustion influences the heat transfer in SI engines. However, the effects of heat transfer on the onset of knock is still not clear due to lack of experimental data of the thermal boundary layer close to the combustion chamber wall. This paper presents measurements of the temperature in the thermal boundary layer under knocking and non-knocking conditions. The temperature was measured using dual-broadband rotational Coherent anti-Stokes Raman Spectroscopy (CARS). Simultaneous time-resolved measurements of the cylinder pressure, at three different locations, and the heat flux to the wall were carried out. Optical access to the region near the combustion chamber wall was achieved by using a horseshoe-shaped combustion chamber with windows installed in the rectangular part of the chamber. This arrangement made CARS temperature measurements close to the wall possible and results are presented in the range 0.1-5 mm from the wall. The engine was run with constant fuel flow under near stoichiometric conditions. Knocking and non-knocking conditions were achieved by using different mixtures of n-heptane and iso-octane. Copyright © 2000 Society of Automotive Engineers, Inc. (Less)