Fuel efficiency improvement and harmful emissions reduction are the main motivations for the development of gas turbine combustors. Numerical computational fluid dynamics (CFD) simulations of these devices are usually computationally expensive since they imply a multi-scale problem. In this work, gaseous non-reactive unsteady Reynolds-Averaged Navier–Stokes and large eddy simulations of a gaseous-fueled radial-swirled lean direct injection combustor have been carried out through CONVERGE™ CFD code by solving the complete inlet flow path through the swirl vanes and the combustor. The geometry considered is the gaseous configuration of the CORIA lean direct injection combustor, for which detailed measurements are available. The emphasis of the work is placed on the demonstration of the CONVERGE™ applicability to the multi-scale gas turbine engines field and the determination of an optimal mesh strategy through several grid control tools (i.e., local refinement, adaptive mesh refinement) allowing the exploitation of its automatic mesh generation against traditional fixed mesh approaches. For this purpose, the normalized mean square error has been adopted to quantify the accuracy of turbulent numerical statistics regarding the agreement with the experimental database. Furthermore, the focus of the work is to study the behavior when coupling several large eddy simulation sub-grid scale models (i.e., Smagorinsky, Dynamic Smagorinsky, and Dynamic Structure) with the adaptive mesh refinement algorithm through the evaluation of its specific performances and predictive capabilities in resolving the spatial-temporal scales and the intrinsically unsteady flow structures generated within the combustor. This investigation on the main non-reacting swirling flow characteristics inside the combustor provides a suitable background for further studies on combustion instability mechanisms.

中文翻译：

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通过先进的网格控制策略模拟贫直接喷射燃气轮机燃烧器中的气态非反应流

燃油效率的提高和有害排放的减少是燃气轮机燃烧室发展的主要动力。这些设备的数值计算流体动力学 (CFD) 模拟通常在计算上很昂贵，因为它们意味着多尺度问题。在这项工作中，通过 CONVERGE™ CFD 代码，通过求解通过涡流的完整入口流动路径，对气态燃料径向涡流稀薄直喷燃烧器进行了气态非反应非定常雷诺平均纳维-斯托克斯和大涡模拟叶片和燃烧器。所考虑的几何形状是 CORIA 稀薄直喷燃烧器的气态配置，可提供详细的测量结果。这项工作的重点是展示 CONVERGE™ 在多尺度燃气涡轮发动机领域的适用性，以及通过几种网格控制工具（即局部细化、自适应网格细化）确定最佳网格策略，从而允许开发其自动网格生成与传统固定网格方法的对比。为此，采用归一化均方误差来量化湍流数值统计与实验数据库的一致性的准确性。此外，工作的重点是研究耦合几个大涡模拟亚网格尺度模型（即 Smagorinsky、Dynamic Smagorinsky、和动态结构）与自适应网格细化算法，通过评估其在解决时空尺度和燃烧器内产生的固有不稳定流动结构方面的特定性能和预测能力。对燃烧器内主要非反应涡流特性的研究为进一步研究燃烧不稳定性机制提供了合适的背景。