Momentum Equation for a Straight Electrically Charged Jet
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摘要: 给出了电场驱动直射流的一维动量守恒方程.该方程是用应力分量表示的,适用于任何流体本构关系,只要流体是不可压缩的.结果显示,为了使方程封闭,需要沿轴向和径向两个方向的本构关系.然而,当附加应力张量的迹为0时,只需要沿轴向的一个本构关系就足够了.还发现,射流的第二主应力差的零阶近似总为0.与其他类型的动量方程做了比较.Abstract: A one-dimensional momentum conservation equation for a straight jet driven by an electrical field was developed. It was presented in terms of the stress component, which could be applied to any constitutive relation of fluids, and the only assumption was that the fluid was incompressible. Our results indicated that both the axial and the radial constitutive relations were required to close the governing equations of the straight charged jet. However, when the trace of the extra stress tensor was zero, only the axial constitutive relation was required. It was also found that the second normal stress difference for the charged jet was always zero. A comparison with other developed momentum equations was made.
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Key words:
- electrically charged jet /
- stability /
- electrospinning
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