解锁加速融合的关键 在离散速度方法中,用于近连续/连续流程中的流量
Linchang Han1, Liming Yang1,2,3, Zhihui Li4
1Department of Aerodynamics, College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China.
Entropy (Basel, Switzerland)
|December 23, 2023
概括
通过加速离散速度方法 (DVM) 计算,在流量模拟中的计算效率得到了提高. 完全隐含的方法和内部代显著降低了航空航天再进入模拟的计算负担.
科学领域:
- 计算流体动力学的流体动力学.
- 航空航天工程是航空航天工程.
- 非平衡气体动态的气体动态
背景情况:
- 在近连续和连续状态下,在不规则物体周围模拟流场是计算密集的.
- 离散速度方法 (DVM) 是解决博尔兹曼-BGK方程的常用方法,但由于空间离散,它面临着高的计算成本.
- 提高计算效率对于航空航天再进入模拟至关重要.
研究的目的:
- 为了加快离散速度方法 (DVM) 计算的趋同.
- 为了减少围绕不规则物体的流场模拟的计算负担.
- 调查隐式离散和内部代对DVM性能的影响.
主要方法:
- 研究了三个DVM版本:半隐含的 (DVM-I),完全隐含的 (DVM-II) 和完全隐含的内部宏观方程代 (DVM-III).
- 在博尔茨曼-BGK方程中实现了对碰撞项的完全隐式离散.
- 利用DVM-III中的宏观控制方程的内部代过程,以改进平衡状态预测.
主要成果:
- 对碰撞项的完全隐性离散使得DVM计算在连续和近连续流量中加速了一次数量级.
- 在DVM-III中添加内部宏观方程代提供了额外的1-2数量级加速.
- 解决宏观方程的计算成本明显低于博尔兹曼-BGK方程.
结论:
- 博尔兹曼-BGK方程的碰撞项的完全隐含的离散是有效的加速DVM.
- 宏观管理方程的内部代提供了实质性的进一步加速.
- 这些进展为模拟近太空环境中的复杂流程提供了一种可行的计算方法.
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