Algorithm Development for Turbulent Combustion Calculations

提出的工作目标是开发，测试和演示新一代的数值方法来解决湍流燃烧的pdf方程。在几个主要工业中，越来越多地使用湍流燃烧模型来帮助设计和开发燃烧装置。这些方法的有用性已经建立，但它可以通过改进建模和计算实现显着增强。PDF方法提供了处理有限速率动力学效应所需的能力，例如NOx的形成和CO的燃烧。然而，重点不是建模问题，而是PDF方法的计算实现。工业需要比现有方法更准确、更可靠、更经济的方法。一种全新的蒙特卡罗方法将被开发来解决pdf方程。它在空间和时间上都是二阶精确的；它将包括一个适用于低速和高速流量的piso型平均压力算法；它将纳入先进的方差减少技术（以减少统计误差）；并且，它将被结构化以在矢量和并行架构上实现。

The objective of the proposed work is to develop, test and demonstrate a new generation of numerical methods to solve the pdf equations for turbulent combustion. In several major industries, there is an increasing use of turbulent combustion models to aid the design and development of combustion devices. The usefulness of these methods has already been established, but it can be significantly enhanced through improvements in the modelling and computational implementation. PDF methods provide the needed capability to handle finite-rate kinetic effects, such as the formation of NOx and the burning of CO. However, the focus is not on modelling issues, but on the computational implementation of pdf methods. Industry requires methods that are much more accurate, robust and economical than those currently available. A radically new Monte Carlo method will be developed to solve the pdf equations. It will be second-order accurate in space and time; it will include a PISO-type mean pressure algorithm applicable both to low-speed and high-speed flow; it will incorporate advanced variance-reduction techniques (to reduce statistical errors); and, it will be structured for implementation on vector and parallel architectures.