| 摘要: |
| 在石油开采与钻探领域，脉冲发生器作为旋转导向系统井下信号传输系统的重要组成部分，提高压力脉冲幅值有助于提升旋转导向系列产品的市场竞争力。为了揭示其工作原理及提高压力脉冲幅值，基于计算流体动力学，利用用户自定义函数（UDF）、动网格技术、非牛顿流体模型，借助Fluent平台对往复节流式正脉冲发生器进行了动态数值实验。利用离散形式的动量方程将主阀体与电磁阀的被动运动转变为主动运动，选择适用于k-ε湍流模型的赫-巴非牛顿流体本构方程描述泥浆，提高了计算的收敛性与运动的可控性。基于非牛顿流体的流固耦合方法，更真实地模拟了脉冲器在井下工作过程。结果表明：限流环内径越小或入口排量越大，则压力脉冲幅值与信号发生频率越大。 |
| 关键词: 正脉冲发生器 动网格 非牛顿流体 动态数值实验 流固耦合 UDF |
| DOI： |
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| Performance Analysis of Reciprocating Throttle Positive Pulse Generator |
| ZHU Ze-xu,YU Kun,JIAO Gang,HU Xiong,CAO Dong-hai |
| (Beijing Institute of Automatic Control Equipment, Beijing 100074, China) |
| Abstract: |
| In the field of petroleum exploitation and drilling, pulse generator is an important part of downhole signal transmission system of rotary steerable system. Increasing the amplitude of pressure pulse is helpful to improve the market competitiveness of rotary steerable series products. In order to reveal its working principle and improve the pressure pulse amplitude, based on computational fluid dynamics, dynamic numerical experiment of reciprocating throttling positive pulse generator is carried out by using User Define Function (UDF), moving grid technology, non-Newtonian fluid model and Fluent platform. The discrete momentum equation is used to change the passive motion of the main valve body and solenoid valve into active motion, and the constitutive equation of the Herschel-Bulkley non-Newtonian fluid suitable for the k-ε turbulence model is selected to describe the mud, which improves the convergence and controllability of the calculation. Based on the fluid-structure interaction method of non-Newtonian fluid, the pulse operation process in the well is simulated more accurately. The results show that the smaller the inner diameter of the current limiting ring, or the larger the inlet displacement, the larger the pressure pulse amplitude and the signal frequency. |
| Key words: Positive pulse generator Moving grid Non-Newtonian fluid Dynamic numerical experiment Bidirectional fluid-structure coupling UDF |
