阻流挡板对液力偶合器环流特性影响规律分析

Two-Phase Circulation Characteristics Prediction of Variable Speed Hydrodynamic Coupling

调速型液力偶合器广泛应用于重型刮板输送机的软启动中,为了提高调速过程中的转矩稳定性,通常在液力偶合器叶轮之间安装阻流挡板。为了分析阻流挡板对偶合器流场及转矩传递特性的影响,针对不同挡板尺寸下的单流道流场计算模型进行数值模拟计算。获得了多工况条件下、不同阻流挡板尺寸时流场数值仿真结果,对比分析了不同工况下挡板对流场转矩特性与流场速度流线分布特性的影响。结果表明,较低充液率时阻流挡板改变了水液环流形式,使输出转矩下降趋势平稳;较高充液率及全充液工况时,挡板降低了环流速度进而减小了输出转矩。分析结果合理预测了阻流挡板对偶合器环流特性的影响规律,为液力偶合器的结构设计与改进提供了可靠的理论依据。

The variable speed hydrodynamic couplings are widely used in the soft start of heavy-duty scraper conveyors. In order to improve the torque stability during speed regulation, a baffle is usually installed between the impellers of the hydrodynamic coupling. In order to analyze the influence of the baffle on the flow field and torque transmission characteristics of the coupling, a numerical simulation calculation was carried out for the flow field calculation model of the single flow channel under different baffle sizes. The results of numerical simulation of flow field under different working conditions and different baffle sizes were obtained. The effects of the baffle on the flow field torque characteristics and the flow field velocity streamline distribution characteristics under different working conditions were compared and analyzed. The results show that the water-liquid circulation form is changed by the baffle at the lower liquid filling rate, and the output torque decreases steadily with the increase of the speed ratio. When the liquid filling rate is high and the liquid filling condition is full, the baffle is passed. The output torque is reduced with the reducing of circulation speed. The analysis results reasonably predict the influence of the baffle on the flow field characteristics of the hydrodynamic coupling, which provides a reliable theoretical basis for the structural design and improvement of the variable speed hydrodynamic coupling.