It is shown that the "damping" effect mainly exists in the zone of 0.5d from the impingement wall, and there are positive as well as adverse pressure gradient in the radial direction.

表明壁面的“阻尼”影响主要集中在近壁面0 . 5D以内，在径向上流动既有顺压梯度，又有逆压梯度。

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The high head produced by the impeller means high adverse pressure gradient within blade passage and because of this the flow often separates from the blade surfaces even at the design point.

低比转速泵的高扬程决定了叶片流道内逆压梯度比较高，这种压力分布使得水流易于在叶片表面脱流分离，这一现象甚至在泵的设计点也难以避免。

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The high head produced by the impeller means high adverse pressure gradient within blade passage and because of this the flow often separates from the blade surfaces even at the design point.

低比转速泵的高扬程决定了叶片流道内逆压梯度比较高，这种压力分布使得水流易于在叶片表面脱流分离，这一现象甚至在泵的设计点也难以避免。

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