往复式泥浆脉冲发生器转子水力转矩

往复式泥浆脉冲发生器是随钻测量（MWD）、随钻测井（LWD）系统的重要组成部分，其转子的水力特性研究对于节约钻井系统能源消耗、提高信号质量、丰富调制方式具有重要意义。由于转子附近机构复杂，湍流现象明显，给研究带来较大困难。利用稳态水力转矩、瞬态水力转矩的相关理论，对发生器中转子水力转矩进行理论分析，利用CFD数值仿真和水力转矩原理实验结果进行验证。研究结果表明，转子在往复式运动中水力转矩基本沿同一方向分布，在10 Hz摆动频率下水力转矩与转子转角密切相关，而与转子角速度及角加速度关系较小，最大水力转矩出现在接近闭合位置。通过加装机械辅助装置，脉冲发生器对电机功率和转矩的需求得到了大幅度的降低。

Hydraulic torque analysis on oscillating mud pulse for MWD/LWD

Reciprocating mud pulse generator is an integral part of Measurement While Drilling (MWD) and Logging While Drilling (LWD) systems. Research on hydraulic characteristics of the generator rotor plays an important role in reducing energy consumption of the drilling system, improving signal quality, and establishing more modulation modes. However, difficulties are encountered in research of the hydraulic characteristics due to the complex peripheral mechanism and obvious turbulent effect of the rotor. In this study, theories of the steady-state hydraulic torque and transient hydraulic torque in hydraulic machinery fluid dynamics are introduced to analyze hydraulic torque of the generator rotor on a theoretical level, and these analysis results can be mutually verified and complemented with the CFD numerical simulation results and experimental results of hydraulic torque working principle. The research results indicate that hydraulic torque exerted on the rotor is basically in the same direction during the whole process of reciprocating motion. The torque is mainly determined by the angle of rotor and hardly by angular velocity and angular acceleration of the rotor at an oscillating frequency of 10Hz. Moreover, the maximum hydraulic torque appears nearly at the closed position. Based on above analysis results, the motor torque and power needed by the pulse generator has been significantly reduced by adding auxiliary mechanical mechanisms.