Large Eddy Simulation of Shear Coaxial Rocket Injector: Real Fluid Effects
Large Eddy Simulation of Shear Coaxial Rocket Injector: Real Fluid Effects
复制标题
剪切同轴火箭喷射器的大涡模拟：真实流体效应
DOI：
10.2514/6.2013-4071
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
S. Thakur
中科院分区：
文献类型：
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作者：
Jean;P. Ma;M. Ihme;S. Thakur
报道了真实流场效应在火箭燃烧室高精度大涡模拟中的实现与验证。非理想流体的行为是使用一个立方彭罗宾逊状态方程建模，一个物理一致的方法是用来转换成原始变量的保守。粘度由Chung等人估计。的方法在超临界气相。在跨临界液相中，提出了一种简单、准确、有效的估算粘度随温度和压力变化的方法。原始热力学变量的高度非线性耦合需要在高密度梯度区域中特别考虑，以避免伪数值振荡。状态方程的非线性的表征确定了高灵敏度的区域。在这些区域中，压力的小的相对变化导致密度和/或温度的显著变化，因此，数值不稳定性倾向于在这些区域中被放大。为了避免非物理振荡，一阶和二阶基本无振荡（ENO）格式局部应用于通量计算的双阈值相对密度传感器识别的面。的传感器和能力的非振荡计划的典型测试用例的评价。最后，这些计划被用来模拟两个典型的情况。
The implementation and verification of real-fluid effects towards the high-fidelity large eddy simulation of rocket combustors is reported. The non-ideal fluid behavior is modeled using a cubic Peng-Robinson equation of state; a thermodynamically consistent approach is used to convert conserved into primitive variables. The viscosity is estimated by Chung et al.’s method in the supercritical gas phase. In the transcritical liquid phase, a simple, accurate and efficient method to estimate the viscosity as a function of temperature and pressure is proposed. The highly non-linear coupling of the primitive thermodynamic variables requires special consideration in regions of high-density gradients to avoid spurious numerical oscillations. The characterization of the non-linearity of the equation of state identifies the regions of high sensitivity. In these regions, small relative changes in the pressure lead to significant changes in density and/or temperature, therefore, numerical instabilities tend to be amplified in these regions. To avoid non-physical oscillations, a first-order and second-order essentially non-oscillatory (ENO) schemes are locally applied to the flux computation on the faces identified with a dual-threshold relative density sensor. The evaluation of the sensor and capabilities of the non-oscillatory schemes on canonical test cases are presented. Finally, these schemes are used to model two canonical cases.