The present work deals with the development of an original Discontinuous Galerkin (DG) finite element code and its application to compute the non-reactive aerodynamics of multicomponent gaseous mixtures in turbulent regime. Recent developments of the DG approach show great potential in computing high-order accurate solutions on arbitrarily complex grids even in the presence of strong discontinuities and thus the method is well suited for modeling combustion aerodynamics. The study of coaxial jets, with and without swirl, is indeed of paramount importance in assessing burner and combustor performance and the accurate understanding of their fluid dynamic behaviour is an essential prerequisite to subsequently investigate their reactive counterpart. The predictive capabilities of the novel method proposed are verified against several experimental tests taken from three different databases, selected to cover the widest range of coaxial jets operating conditions, and compared with simulations carried out using a commercial code, at most second-order accurate. Notwithstanding the numerical prediction of turbulent gaseous mixture is indeed challenging, it is shown that the DG method exhibits a good accuracy level even on coarse grids and allows to properly resolve the relevant jet structures and characteristic features.

本工作涉及原始不连续伽勒金（DG）有限元代码的开发及其在湍流状态下计算多组分气体混合物的非反应空气动力学的应用。DG方法的最新发展显示出即使在存在强不连续性的情况下，在任意复杂的网格上计算高阶精确解的巨大潜力，因此该方法非常适合于对燃烧空气动力学进行建模。在评估燃烧器和燃烧室的性能时，对带或不带涡流的同轴射流的研究确实至关重要，准确了解其流体动力特性是随后研究其反应性的必要前提。相对于从三个不同的数据库中进行的几次实验测试，验证了所提出的新方法的预测能力，这些实验被选择为涵盖了最广泛的同轴射流工作条件，并与使用商业代码进行的模拟进行了比较，其精度最高为二阶。尽管对湍流气态混合物进行数值预测确实具有挑战性，但事实表明，DG方法即使在粗网格上也显示出良好的精度水平，并且可以适当解决相关的射流结构和特征。