Shock control bumps can be used to control and weaken the shock waves that form on engine intakes at high angles of attack. In this paper, it is demonstrated how shock control bumps applied to an engine intake can reduce or eliminate shock-induced separation at high incidence, and also increase the incidence at which critical separation occurs. Three-dimensional Reynolds-average Navier–Stokes (RANS) simulations are used to model the flow through a large civil aircraft engine intake at high incidence. The variation in shock strength and separation with incidence is first studied, along with the flow distribution around the nacelle. An optimisation process is then employed to design shock control bumps that reduce shock strength and separation at a fixed high incidence condition. The bump geometry is allowed to vary in shape, size, streamwise position and circumferential direction around the nacelle. This is shown to be key to the success of the shock control geometry. A further step is then taken, using the optimisation methodology to design bumps that can increase the incidence at which critical separation occurs. It is shown that, by using this approach, the operating range of the engine intake can be increased by at least three degrees.

中文翻译：

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使用冲击控制凸块来提高发动机进气性能和可操作性

冲击控制凸块可用于控制和削弱在发动机进气口以高迎角形成的冲击波。在本文中，展示了应用于发动机进气口的冲击控制凸块如何减少或消除高发生率时由冲击引起的分离，并增加发生临界分离的发生率。三维雷诺平均纳维-斯托克斯 (RANS) 模拟用于模拟以高发生率通过大型民用飞机发动机进气口的流动。首先研究了冲击强度和分离随入射角的变化，以及机舱周围的气流分布。然后采用优化过程来设计冲击控制凸块，以在固定的高发生率条件下降低冲击强度和分离。凹凸几何形状允许在形状、大小、机舱周围的流向位置和圆周方向。这被证明是冲击控制几何结构成功的关键。然后采取进一步的步骤，使用优化方法来设计可以增加临界分离发生率的凸块。结果表明，通过这种方法，发动机进气的工作范围至少可以增加三度。