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

1032930 sicko发生在热燃烧气体和冷壁之间的内燃机热传递在一些旨在提高燃油经济性和减少污染物形成的先进发动机概念中被认为是最重要的。传热速率最终取决于沿缸内壁面的边界层型流动。这些边界层内部的潜在物理机制仍然没有得到很好的理解。由于缺乏对壁面附近气体速度和温度分布的详细测量，阻碍了可用于设计目的的模型的发展。智力优势：这项研究将产生关于内燃机内部高瞬态边界层内速度和温度分布的详细实验信息。速度数据将使用具有高重复率激光源的微粒子图像测速技术获得。温度分布将用激光诱导荧光测定。将确定整体平均速度和温度数据，以及在相对较宽的工作参数范围内的两点、自动和相互关系参数，用于透明发动机在机动和点火模式下的测试。墙体热流密度数据将同时获得。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传热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因素。这项研究将涉及研究生培训，包括学生的国际经验。本科生也将与达姆施塔特工业大学的合作者一起工作。研究生将参加各种旨在为女性从事工程职业做准备的活动。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.