The recent growing interest in urban air mobility (UAM) worldwide has led to the demand for physical analyses of the aerodynamic performance and aeroacoustic characteristics of electric vertical takeoff and landing (eVTOL) rotorcraft. In a UAM eVTOL rotorcraft, the smaller vortices generated from multiple propulsors interact with lifting surfaces such as wings, fuselage, and propellers in a complex manner. Therefore, to accurately predict the performance and noise of UAM eVTOL rotorcraft, vortices should be preserved with little dissipation; and their interactions must be modeled precisely. These requirements need a numerical algorithm with a refined resolution than that allowed by conventional schemes. This paper proposes a newly modified enhanced multidimensional limiting process (eMLP) for vorticity conservation (eMLP-VC), which improves the original eMLP by accounting for the fact that most rotorcraft flowfields are vortex dominated and subsonic. For advanced capability in preserving vortices, the distinguishing criterion was modified through vortex profile analysis, and low-Mach-number adjustment was performed by reconstructing the interpolated primitive variables. The proposed scheme was applied to wave propagation, shock discontinuity, double Mach reflection, propeller–wing interaction, and Second Higher-Harmonic Control Aeroacoustic Rotor Test problems. The computed results confirmed that eMLP-VC exhibits superior resolution, numerical stability, and computational time efficiency as compared to the multidimensional limiting process, eMLP, and weighted essentially nonoscillatory methods.

最近全球对城市空中交通 (UAM) 的兴趣日益浓厚，导致需要对电动垂直起降 (eVTOL) 旋翼机的空气动力学性能和气动声学特性进行物理分析。在 UAM eVTOL 旋翼机中，多个推进器产生的较小涡流以复杂的方式与升力面（例如机翼、机身和螺旋桨）相互作用。因此，要准确预测 UAM eVTOL 旋翼机的性能和噪声，应保持涡流且耗散很小；并且它们的相互作用必须精确建模。这些要求需要一种比传统方案所允许的分辨率更高的数值算法。本文提出了一种新改进的增强多维限制过程（eMLP）用于涡度守恒（eMLP-VC），它通过考虑大多数旋翼飞机流场是涡流主导和亚音速的事实来改进原始 eMLP。为了保持涡流的先进能力，通过涡流剖面分析修改了区分标准，并通过重建插值的原始变量进行低马赫数调整。所提出的方案被应用于波传播、冲击不连续性、双马赫反射、螺旋桨-机翼相互作用和二次高谐波控制气动声学转子测试问题。计算结果证实，与多维限制过程、eMLP 和加权基本非振荡方法相比，eMLP-VC 具有更高的分辨率、数值稳定性和计算时间效率。