This study is aimed at evaluating the energy saving benefit and its limitation of the boundary layer ingestion (BLI) applied to a transonic blended-wing-body (BWB) aircraft. The power balance method is adopted in the aerodynamic performance analysis of the aircraft. We further improve the one-dimensional analysis framework by adding the pressure volumetric work term in the power balance equation for the application in compressible flow with shock wave regions. A determining expression for the power-saving coefficient (PSC) of the BLI effect is also deduced, which is related to a BLI fraction, the airframe dissipation component ratios, and the specific thrust of the propulsor. This expression provides a way for the preliminary evaluation and comparison of BLI benefits applied in different aircraft configurations. The flow quantities of three different configurations are obtained by 3D Reynolds-averaged Navier–Stokes (RANS) numerical simulations for the calculation of aerodynamic dissipation components. The grid refinement and domain size study shows that the calculated force coefficients and total dissipation coefficient have a good convergence characteristic with the mesh refinement and are insensitive to the variation in domain size. The evaluated PSC of the BWB aircraft with a BLI propulsor is 5% using the previously developed determining expression. The maximum of PSC is 18.8%. The following comparison of dissipation components for the power-on and power-off cases shows that the benefit of BLI is slightly underestimated by the determining expression of PSC. The reason is that the variation in the boundary layer velocity profile at the trailing edge of the center body part is neglected, which is due to the installation of the propulsor. Furthermore, when the BLI propulsor is applied to a BWB aircraft, the variation in trailing edge vortex dissipation and volumetric pressure work term should be studied in detail.

中文翻译：

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基于能量的边界层进气融合翼体飞机气动分析

本研究旨在评估应用于跨音速混合翼体 (BWB) 飞机的边界层摄取 (BLI) 的节能效益及其限制。飞机气动性能分析采用功率平衡法。我们通过在功率平衡方程中添加压力体积功项来进一步改进一维分析框架，以应用于具有冲击波区域的可压缩流动。还推导出了BLI效应的节电系数（PSC）的确定表达式，它与BLI分数、机身耗散分量比和推进器的比推力有关。该表达式为初步评估和比较应用于不同飞机配置的 BLI 效益提供了一种方法。通过 3D Reynolds 平均 Navier-Stokes (RANS) 数值模拟获得三种不同配置的流量，用于计算气动耗散分量。网格细化和域尺寸研究表明，计算得到的力系数和总耗散系数与网格细化具有良好的收敛性，对域尺寸的变化不敏感。使用先前开发的确定表达式，带有 BLI 推进器的 BWB 飞机的评估 PSC 为 5%。PSC 的最大值为 18.8%。以下通电和断电情况下的耗散分量比较表明，PSC 的确定表达式略微低估了 BLI 的好处。原因是由于安装了推进器，忽略了中心体部分后缘边界层速度剖面的变化。此外，当BLI推进器应用于BWB飞机时，应详细研究后缘涡耗散和体积压力功项的变化。