数值计算结果表明,顺压梯度有明显的延缓转捩作用,逆压梯度有较强的不稳定作用。
The numerical calculation results show that the favorable pressure gradients have apparent laminar flow control property, and the unfavorable pressure gradients have a strong unstable influence.
在零压力梯度下,这个局部的动量损失几乎是一个附加的常量,而逆压梯度则会扩大这种动量损失。
In zero pressure gradient flow, this local momentum loss is Minost an additive constant quantity. On the other hand, adverse pressure gradient results in amplification of this momentum loss.
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。
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.
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。
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.
破坏出现的主要位置应是钻头头部多喷嘴之间的区域、喷嘴本身及其周围区域和筋板及流道的逆压力梯度区。
Bit damage maybe occur on the area of bit wall around the nozzles, nozzles area and inverse pressure gradient area.
破坏出现的主要位置应是钻头头部多喷嘴之间的区域、喷嘴本身及其周围区域和筋板及流道的逆压力梯度区。
Bit damage maybe occur on the area of bit wall around the nozzles, nozzles area and inverse pressure gradient area.
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