Mass and energy exchange processes in transient high-pressure and high-temperature boundary layers

1032930发生在热燃烧气体和冷却器壁之间的内燃机热传递预计在旨在提高燃料经济性和减少污染物形成的几种先进发动机概念中具有首要重要性。传热速率最终由沿缸内壁沿着的边界层型流动决定。这些边界层内的基本物理机制仍然没有得到很好的理解。一个缺乏详细的测量气体速度和温度分布附近的墙壁阻碍了模型的发展，可用于design purposes.智力优点：这项研究将产生详细的实验信息的速度和温度分布内发生在内燃机内的高瞬态边界层。速度数据将使用高重复频率激光源的微粒子图像测速技术获得。将使用激光诱导荧光测定温度分布。将确定整体平均速度和温度数据，以及在发动机和点火模式下透明发动机试验的相对宽的操作参数范围内的参数的两点、自动和互相关。同时采集壁面热通量数据。这些数据将被合作者用于开发和验证这种复杂和高度瞬态现象的计算模型。更广泛的影响：了解和预测内燃机壁面热传递的能力是未来发动机设计中减少污染物形成和提高燃油效率所必需的关键要素。这项研究将涉及研究生培训，包括学生的国际经验。本科生还将与达姆施塔特技术大学的合作者一起工作。研究生将参加旨在为妇女从事工程职业做准备的各种举措。还计划向非传统受众广泛传播。

1032930SickInternal combustion engine heat transfer that occurs between hot combustion gases and the cooler walls is expected to be of primary importance in several advanced engine concepts aimed at increasing fuel economy and reducing pollutant formation. The heat transfer rates are ultimately determined by boundary layer-type flow along the in-cylinder walls. The underlying physical mechanisms within these boundary layers are still not well understood. A paucity of detailed measurements of gas velocity and temperature distributions adjacent to the walls has hindered the development of models that could be used for design purposes.Intellectual Merit: This research will generate detailed experimental information regarding the velocity and temperature distributions within highly-transient boundary layers that occur within internal combustion engines. Velocity data will be acquired using a micro-particle image velocimetry technique with a high repetition rate laser source. Temperature distributions will be determined using laser induced fluorescence. Ensemble-averaged velocity and temperature data will be determined, as will two-point, auto-, and cross-correlation of parameters over a relatively wide range of operating parameters for transparent engine tests in both the motored and fired modes. Wall heat flux data will be simultaneously acquired. The data will be used by collaborators to develop and validate computational models of this complex and highly transient phenomena.Broader Impacts: The ability to understand and predict wall heat transfer in internal combustion engines is a key element necessary to reduce pollutant formation and increase fuel efficiency in future engine designs. This research will involve graduate student training, including an international experience for the student. Undergraduate students will also work with collaborators at the Technical University of Darmstadt. The graduate student will participate in various initiatives aimed at preparing women for careers in engineering. Broad dissemination to non-traditional audiences is also planned.