Presidential Young Investigators Award: Engine Heat Transfer and Combustion Studies

单缸研究发动机将用于测量瞬时壁面温度、对流和辐射热通量、燃烧室压力和其他相关的流场参数，以及废气排放。结果将被用于开发新一代多维过程模型，该模型将适用于使用现有超级计算机的低热排出(LHR)和常规发动机的真实模拟。这些模型的基础将是Los Alamos Kiva-II计划，该计划可以提供气缸内流体和燃烧过程的详细知识。改进的气壁换热模型将边界层现象与湍流和燃烧过程联系起来，将缸内辐射与碳烟动力学联系起来。燃烧室部件的多维有限元描述也将纳入代码中。因此，将研究周期性变化的气壁换热现象、部件内部的瞬时热传导、非定常边界层和沉积特性，以及发动机的燃烧和排放现象。建议的发动机传热学和燃烧研究将加深我们对常规和LHR发动机燃烧室中非稳态热现象的基本理解。这一新知识将用于优化由于在发动机燃烧室中引入陶瓷材料、先进的部件设计以及新的燃料和润滑油而产生的性能和排放权衡。实验研究还将提供实际的边界条件，用于我们的分析模型，以预测传统燃烧室和LHR燃烧室部件的瞬时温度分布、热应力水平和润滑要求。这一协调的研究工作利用了先进的仪器设备和不断增长的计算机能力，可以为我们生产出更省油、排放特性可接受的发动机做出重大贡献。

A single-cylinder research engine will be instrumented for measurements of instantaneous wall surface temperatures, convective and radiative heat fluxes, combustion chamber pressure and other pertinent flow-field parameters, and exhaust emissions. The results will be used to develop a new generation of multi-dimensional process models which will be suitable for realistic simulation of Low-Heat Rejection (LHR) and conventional engines using available supercomputers. The basis for these models will be the Los Alamos Kiva-II program which can provide a detailed knowledge of in-cylinder fluid and combustion processes. Improved gas-to-wall heat transfer models will relate boundary layer phenomena to turbulence and combustion processes and in-cylinder radiation to soot dynamics. Multi-dimensional finite element descriptions of the combustion chamber components will also be incorporated into the code. Thus, cyclically-varying gas-to-wall heat transfer phenomena, transient heat conduction inside the components, unsteady boundary layer and deposit characteristics, and engine combustion and emissions phenomena will be studied. The proposed engine heat transfer and combustion studies will enhance our basic understanding of the unsteady thermal phenomena in conventional and LHR engine combustion chambers. This new knowledge will be used to optimize the performance and emissions trade-offs resulting from the introduction of ceramic materials, advanced component designs, and new fuels and lubricants in the engine combustion chamber. The experimental studies will also provide realistic boundary conditions which will be used in our analytical models to predict transient temperature distributions, thermal stress levels, and lubrication requirements of conventional and LHR combustion chamber components. This coordinated research effort which takes advantage of advanced instrumentation and ever-increasing computer capability can make a substantial contribution in our efforts to produce more fuel efficient engines with acceptable emissions characteristics.