DADOREN: Direct numerical simulations And Data-driven analysis Of ignition and combustion in Realistic pre-chamber/ Engine systems with NH3/H2 blend fuel

为了促进实际发动机系统中的无碳和低排放燃烧，本项目研究了NH3/H2混合燃料在真实预燃室/发动机几何形状中的瞬态点火和湍流燃烧过程。直接数值模拟（DNS）进行了这个系统的亿级计算的超级计算机上，产生大量的高保真数据。机器学习技术被应用于加速DNS中的化学动力学计算。用浸入边界法来表示真实的几何形状。通过数据驱动分析，详细研究了湍流火焰的点火特性和多尺度特性。NOx排放也进行了研究。对NH_3/H_2燃料预燃室/发动机系统的实际情况有了更深入的了解，这对基础理论研究和实际应用都有重要意义。

To facilitate carbon-free and low emission combustion in practical engine systems, this project investigates the transient ignition and turbulent combustion process in a realistic pre-chamber/engine geometry with NH3/H2 blend fuel. Direct numerical simulations (DNS) are carried out for this system with exascale computation on Supercomputers, generating a vast amount of high-fidelity data. Machine learning techniques are applied to accelerate the chemical kinetic computation in DNS. The realistic geometry is represented by the immersed boundary method. Data-driven analysis is done to investigate in detail the ignition characteristics and the multi-scale features of the turbulent flames. NOx emissions are also investigated. A better understanding of the practical pre-chamber/engine system using NH3/H2 fuel should be finally obtained, which would be useful for both fundamental academic research and practical applications.