Abstract: The effect of temperature on flow characteristics of NLGI 3 lithium grease in circular pipelines was investigated. The rheological behavior was examined by using rotational rheometer and the models for velocity and stress fields were established by combining the experimental results and theoretical analysis. The experimental results show that the lithium grease presents high yield shear stresses, excellent viscosity-temperature characteristics and shear-shinning behavior. The yield stress and viscosity decrease as temperature increases, improving the fluidity. The relationships between pipeline flow characteristics and influencing factors are given by using the mathematical model described through MATLAB programming and drawing. The effect of temperature on flow characteristics indicates that higher medium temperature is in favor of lithium grease transportation.

Key words: temperature, lubricating grease, non-Newtonian fluid, rheology, velocity field, stress field, flow characteristics

摘要： 为研究温度对润滑脂圆管流动特性的影响规律，采用旋转流变仪分析了润滑脂的流变特性，并基于流变特性研究结果和理论分析建立了润滑脂圆管流的速度场和应力场变化模型。结果表明：润滑脂具有高的屈服剪应力，表现出良好的黏温特性和剪切稀化特性，温度升高润滑脂的屈服应力和表观黏度均下降，表现为更好的流动性；利用MATLAB编程绘图对速度场和应力场分析，给出了润滑脂圆管流动特性规律的影响因素及变化关系；揭示了温度对润滑脂圆管流动特性的影响规律，提高输送介质温度利于润滑脂的输送。

关键词: 温度, 润滑脂, 非牛顿流体, 流变学, 速度场, 应力场, 流动特性