论文标题

对于化学反应的Navier-Stokes方程的保守性不连续的Galerkin离散化

A Conservative Discontinuous Galerkin Discretization for the Chemically Reacting Navier-Stokes Equations

论文作者

Johnson, Ryan F., Kercher, Andrew D.

论文摘要

我们提供了对多组分化学反应可压缩的Navier-Stokes方程的不连续的Galerkin有限元法(DG)的详细描述和验证,该方程保留了DG的理想特性,即流动区域的平滑区域中的离散保护和高阶精度。通过对热力学模型和所得弱形式的一致评估以及适当的淋巴结基础,保持相邻元素之间的压力平衡。因此,离散化不会在流动的平滑区域或温度连续的材料界面中产生非物理压力振荡。此外,我们提出了一种用于求解普通微分方程Dgode系统的HP自适应DG方法,该方法用于解决由于僵硬的化学反应而引起的物种浓度的时间演化。将耦合求解器应用于几个具有挑战性的测试问题,包括多组分的冲击流以及化学反应的爆炸,deflagrations和带有详细动力学的剪切流。我们证明,离散化不会产生非物理压力振荡,并且在适用的情况下,我们验证其保持离散保护。求解器还显示出在爆炸过程中再现预期的温度和物种特征以及预期的二维细胞爆炸结构。我们还证明,对于一维预混合火焰的情况,求解器可以产生准确的,高阶的温度和物种剖面近似值,而无需人工稳定。最后,提出了二维和三维多组分化学反应剪切流的高阶溶液,而没有任何额外的稳定性。

We present a detailed description and verification of a discontinuous Galerkin finite element method (DG) for the multi-component chemically reacting compressible Navier-Stokes equations that retains the desirable properties of DG, namely discrete conservation and high-order accuracy in smooth regions of the flow. Pressure equilibrium between adjacent elements is maintained through the consistent evaluation of the thermodynamics model and the resulting weak form, as well as the proper choice of nodal basis. As such, the discretization does not generate unphysical pressure oscillations in smooth regions of the flow or at material interfaces where the temperature is continuous. Additionally, we present an hp-adaptive DG method for solving systems of ordinary differential equations, DGODE, which is used to resolve the temporal evolution of the species concentrations due to stiff chemical reactions. The coupled solver is applied to several challenging test problems including multi-component shocked flows as well as chemically reacting detonations, deflagrations, and shear flows with detailed kinetics. We demonstrate that the discretization does not produce unphysical pressure oscillations and, when applicable, we verify that it maintains discrete conservation. The solver is also shown to reproduce the expected temperature and species profiles throughout a detonation as well as the expected two-dimensional cellular detonation structure. We also demonstrate that the solver can produce accurate, high-order, approximations of temperature and species profiles without artificial stabilization for the case of a one-dimensional pre-mixed flame. Finally, high-order solutions of two- and three-dimensional multi-component chemically reacting shear flows, computed without any additional stabilization, are presented.

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