A Simple Device for Preventing Turbulent Contamination on Swept Leading Edges
A Simple Device for Preventing Turbulent Contamination on Swept Leading Edges
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一种防止后掠前缘湍流污染的简单装置
DOI：
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发表时间：
1965
期刊：
影响因子：
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通讯作者：
M. Gaster
中科院分区：
文献类型：
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作者：
M. Gaster
在非后掠机翼上，或在具有少量后掠的机翼上，绕前缘的有利的压力梯度，即气流迅速加速离开驻点线的地方，保证了一定量的层流，只要机翼表面足够光滑。然而，在大后掠机翼上，已经发现紊流可以存在于附着线本身上，因此没有自然出现的层流区。这个问题是由机翼根部的紊流引起的，紊流沿着附着线扫过。如果这个紊流附着线边界层的雷诺数大于某个临界值，整个附着线边界层保持紊流，整个机翼被污染。但当雷诺数低于临界值时，湍流沿前缘沿着衰减，附着线上的边界层又恢复到层流状态。当前缘半径很小，机翼只是轻微后掠时，就会出现这种情况。附着线边界层雷诺数Rθ由下式给出：
On unswept wings, or wings with small amounts of sweep, the favourable pressure gradient round the leading edge, where the flow is rapidly accelerated away from the stagnation line, ensures a certain amount of laminar flow, provided the wing surface is sufficiently smooth. On highly swept wings, however, it has been found that turbulent flow can exist on the attachment line itself and there are therefore no naturally occurring regions of laminar flow. This trouble arises from the turbulence at the root of the wing, which sweeps along the attachment line. If the Reynolds number of this turbulent attachment line boundary layer is greater than some critical value, the whole attachment line boundary layer remains turbulent and the complete wing is contaminated. But if the Reynolds number is below the critical value, the turbulence decays along the leading edge and the boundary layer on the attachment line reverts back to the laminar state. This situation arises when the leading edge radius is small and the wing is only slightly swept. The attachment line boundary layer Reynolds number, Rθ, is given by the following equation: