Control of the boundary layer upstream and in the region of the engine inlet is an important consideration for airplane designers. One important aspect of this problem can be seen in the performance analysis of submerged inlets for which the design is based on boundary layer ingestion. With a large offset between the flush entrance and the compressor face, these low drag concepts are suitable for stealth applications, but when the wetted area upstream of the inlet is long, the ingestion of thickened boundary layer results in flow separation at the bends, pressure recovery losses and finally reduction of thrust. In this paper, a ridge surface is used as a passive integration solution to prevent the upstream boundary layer from entering into the inlet. To investigate the new integration method, a submerged inlet with a triangular entrance is designed and its flow pattern is simulated numerically by ANSYS Fluent solver with and without the ridge configuration. The vortex structures, breakdowns, boundary layer transition and efficiency factors are determined by second order accuracy and use of two different structural mesh domains and flow solvers. Results indicate that the ridge surface improves the inlet efficiency significantly from low to high-subsonic flow regimes and a variety of sideslip angles.

控制上游和发动机进口区域的边界层是飞机设计者的一个重要考虑因素。这个问题的一个重要方面可以在设计基于边界层摄入的淹没入口的性能分析中看到。由于齐平入口和压气机面之间有很大的偏移，这些低阻力概念适用于隐身应用，但是当入口上游的润湿区域很长时，加厚的边界层的摄入导致弯曲处的流动分离，压力恢复损失并最终减少推力。在本文中，脊面用作被动集成解决方案，以防止上游边界层进入入口。为了研究新的积分方法，设计了一个带三角形入口的浸没式入口，并通过ANSYS Fluent求解器对有和没有脊配置的水流模式进行了数值模拟。涡流结构、击穿、边界层过渡和效率因子由二阶精度和两种不同结构网格域和流动求解器的使用决定。结果表明，脊表面显着提高了从低到高亚音速流态和各种侧滑角的入口效率。