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Simulation program based on the theory of drift-flux and hydraulic model was finished in consideration of the influence of pipe angle on distribution parameter C0 and drift velocity Vgj within thermodynamic system two-phase flow. A research was carried out using a simplified hydraulic model in which the void fraction was calculated by iteration; according to the computing result of both adiabatic and uniform heated two-phase pipelines, the comparison was given, and the details showed that theoretical analysis was well agreed with experimental results and provided a refer- ence for engineering application.
本文设计了一种适用于狭长空间环境的双向圆极化微带天线。天线为双层结构的二元阵，下层为激励二元阵、上层为寄生二元阵，馈电点位于下层的几何中心。首先，利用切角的方式实现了圆极化，再通过近乎中心对称的电流分布实现了天线的双向辐射特性。在天线中心频率1.9 GHz上实现了夹角为72？的双向圆极化辐射，相对阻抗带宽约为8.2%，最大辐射方向上相对轴比带宽(AR < 3dB)2.1%，增益约为5.7 dBi。
A bi-directional and circularly polarized microstrip patch antenna is proposed for applications in the long corridor environment. This antenna consists of two substrate layers, in which binary- element patch array is at the bottom and parasitic binary element array is on top layer. It is center-fed from the bottom layer. Firstly, the circular polarization is achieved by means of truncating corners. Secondly, the bi-direction pattern is realized with the nearly symmetrical current distribution. A bi-directional radiation pattern has been achieved at the center-frequency of 1.9 GHz. The relative impedance bandwidth is about 8.2%, while the axial ratio bandwidth is about 2.1% at maximum radiation direction. The gain is about 5.7 dBi.