Turbulent combustion modelling for conditions relevant to industrial applications

在世界范围内，对交通运输和发电的空气污染物排放实施了越来越严格的规定。油价的不确定性进一步加速了对替代燃油效率和低排放发电系统的探索。实验研究在研究工业燃烧室中出现的问题中起着重要作用；然而，由于成本和大的周转时间，综合实验不能常规运行。因此，显然需要开发能够预测瞬态现象的计算工具，特别是点火和熄灭，以及用于设计和优化工业燃烧器和发动机的各种燃料的温度和排放水平。***本提案概述了一项研究计划，其长期目标是开发一种有效和准确的计算方法和模型，用于预测与发电和运输行业相关的各种燃烧工况下的火焰特性和污染物排放。拟议方案的两个短期目标侧重于需要不同物理建模考虑的两个关键方面：在与工业应用相关的条件下，对选定情况下的瞬态现象（如熄灭和着火）进行准确预测。精确模拟燃烧过程燃烧复杂的燃料混合物使用详细的化学，重点是大气污染物的预测。***拟议的研究计划建立在我们最近开发的条件源项估计（CSE）方法的基础上，使它们达到更高的发展水平，并提高了在工业应用中预测复杂燃料的点火/熄灭和大气排放的信心。将选择来自物理复杂性不断增加的情况的实验数据集，以涵盖在工业燃烧室和发动机中发现的不同条件和现象。这些案例提供了评估着火/熄灭预测的数据，并生成燃烧稳定性图，以及复杂燃料混合燃烧过程的准确性。准确的，下一代化学表将阐述，包括微分扩散。大多数模拟将在大涡模拟（LES）中运行，并使用雷诺兹平均纳维尔斯托克斯（RANS）方法进行一些发展。***这些工具将被设计成多功能和自动化，需要最少的用户输入。待开发的技术与工程和研究界直接相关，因为它们将有助于改进和有效地预测和调查燃气轮机、炉子和锅炉等工业系统中的火焰稳定、点火/熄灭和排放。

Increasingly stringent regulations on airborne pollutant emissions for transportation and power generation are being imposed worldwide. Uncertainties in oil prices have further accelerated the search for alternative fuel-efficient and low-emission power generation systems. Experimental studies play an important role in the investigation of the issues arising in industrial combustion chambers; however, comprehensive experiments cannot be run routinely due to cost and large turnaround times. Thus, there is a clear need to develop computational tools capable of predicting transient phenomena, specifically ignition and extinction, as well as temperatures and emission levels for various fuels for design and optimization of industrial burners and engines. ***This proposal outlines a research program with the long-term objective of developing an efficient and accurate computational methods and models for the prediction of flame characteristics and pollutant emissions in the diverse combustion operating conditions relevant to those found in the power generation and transport industry. The two short-term objectives of the proposed program focus on two key aspects that require different physical modelling considerations: ***i. Accurate prediction of transient phenomena such as extinction and ignition for selected cases in conditions relevant to industrial applications.***ii. Accurate simulation of combustion processes burning complex fuel blends using detailed chemistry with emphasis on atmospheric pollutant predictions. ***The proposed research program builds upon our recently developed Conditional Source-term Estimation (CSE) methods to bring them to a much higher level of development and improved confidence for the prediction of ignition/extinction and atmospheric emissions from complex fuels, in industrial applications. Experimental data sets from situations with increasing physical complexity will be selected to cover different conditions and phenomena that are found in industrial combustion chambers and engines. These cases present data with which to assess the prediction of ignition/extinction and generate maps for combustion stability, as well as the accuracy of the combustion process for complex fuel blends. Accurate, next-generation chemistry tables will be elaborated that include differential diffusion. Most simulations will be run in Large Eddy Simulation (LES) with a few developments using a Reynolds Averaged Navier Stokes (RANS) approach.***The tools will be designed to be versatile and automated, requiring minimal user input. The techniques to be developed are of direct relevance to the engineering and research community as they will facilitate improved and efficient prediction and investigation of flame stabilization, ignition/extinction and emissions in industrial systems such as gas turbines, furnaces and boilers.