Anomalous phenomena in pressure drops of water flows through micro-orifices
Anomalous phenomena in pressure drops of water flows through micro-orifices
复制标题
水流通过微孔压降的异常现象
DOI：
10.1007/s10404-014-1362-6
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发表时间：
2014
影响因子：
2.8
通讯作者：
and Takatsune Narumi
中科院分区：
文献类型：
--
作者：
Akiomi Ushida;Tomiichi Hasegawa;and Takatsune Narumi
测量了高速水流通过不同直径微孔时的压降。对于直径为400和100μm的节流孔，观测到的压降值与N-S方程的预测值吻合较好，但对于直径小于50μm的节流孔，观测到的压降值低于预测值。特别是，对于直径为10和5μm的节流孔，测量的压降值几乎比预测值低两个数量级。考虑了几个可能导致压降降低的因素，包括孔口形状和孔板的变形，但没有一个因素被证明足够显著，从而导致如此大的压降。孔板流动中的弹性应力似乎是压降减小的最可能原因。用喷流推力法估算的弹性应力依赖于通过微孔的平均速度，这有力地支持了水流的弹性。
Pressure drops were measured for high-velocity water flows through micro-orifices of various diameters. The observed pressure drop values agreed well with the values predicted by the Navier–Stokes equation for 400 and 100 μm diameter orifices, but were lower than the predicted values for orifices less than 50 μm in diameter. In particular, the measured pressure drop value was almost two orders of magnitude lower than the predicted value for the 10 and 5 μm diameter orifices. Several factors that may cause a reduction in pressure drop were considered, including orifice shape and deformation of the orifice foil, but none proved to be significant enough to cause such a large reduction. Elastic stress in orifice flow appeared to be the most plausible cause of the pressure drop reduction. The elastic stress, which was estimated by the jet thrust method, was found to be dependent on the mean velocity passing through the micro-orifices, which strongly supported the elasticity of water flows.