Abstract The article deals with an implicit formulation of the pressure far field boundary condition, also known as the characteristic boundary condition, in a pressure-based coupled solver. This boundary condition applies to compressible flows over the entire Mach regime, and is derived by invoking the Riemann invariants to implicitly express the flow variables at inlets and outlets in terms of their values inside the domain. A set of inviscid an turbulent flow cases that include pressure far field boundary conditions are tested, namely: low subsonic compressible flow past a NACA0012 airfoil at 10° angle of attack; transonic flow over circular bump; supersonic flow over a series of slender bumps; and DLR-F6 Wing-Body-Nacelle-Pylon Aircraft. Predictions using the prescribed coupled solver are in good agreement with similar results obtained with density-based methods and/or experimental data.

中文翻译：

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完全耦合的基于压力的流动求解器中特征边界条件的隐式实现

摘要 本文讨论了基于压力的耦合求解器中压力远场边界条件（也称为特征边界条件）的隐式公式。该边界条件适用于整个马赫范围内的可压缩流动，并且是通过调用黎曼不变量以根据域内的值隐式表达入口和出口处的流动变量而导出的。测试了一组包含压力远场边界条件的无粘性湍流案例，即： 低亚音速可压缩流通过 NACA0012 机翼，攻角为 10°；圆形凸起上的跨音速流动；超音速流过一系列细长的颠簸；和 DLR-F6 翼身-机舱-挂架飞机。