凸轮转子泵抽送不同浓度非牛顿流体的流场分析及对性能影响

Analysis of Flow Field and Performance Effect of Rotary Lobe Pump Pumping Non-Newtonian Fluids with Different Concentration

为了探讨摆线型凸轮转子泵抽送粪污介质的性能变化和针对非牛顿流体类抽送的优化设计,以三叶摆线型凸轮转子泵作为研究对象,选取清水和浓度为6.87%,9.20%,12.15%的猪粪作为抽送介质,对凸轮转子泵进行三维非定常数值模拟,分析内部流场瞬态特性,预测其外特性。分析结果表明:在抽送清水和不同浓度的猪粪时,从泵腔的进口区域到出口区域的压力逐渐升高,随猪粪浓度增大,独立工作腔室的压力增大;抽送非牛顿流体时,间隙处因挤压而产生的速度激增,转子泵腔内的速度分布更加均匀;出口的压力脉动主频均出现在2倍叶频处,压力脉动幅值随猪粪浓度增大而减小;随猪粪浓度增大,出口流量、容积效率及水力效率增大,流量脉动系数减小,其性能优于抽送清水介质。研究为凸轮转子泵输送非牛顿流体时的优化设计奠定了基础。

In order to explore the influence of the non-Newtonian fluid on the performance of the rotary lobe pump,with three-lobe cycloid rotor pump being treated as research object.Water and pig manure with concentrations of 6.87%,9.20%,and 12.15%are used as pumping fluids,the numerical calculation of the 3D transient flow in the rotary lobe pump was carried out,and the transient flow characteristics,performances are analyzed.The results indicate that when pumping water and pig manure of different concentrations,the pressure from the inlet area of the pump to the outlet area gradually increases.As the concentration of pig manure increases,the pressure of independent work chamber increases.When pumping the non-Newtonian fluids,the speed increase in the gap due to extrusion,the speed is distributed is more uniformly in the pumps.As the concentration of pig manure increases,the frequency of the pressure pulsation in the outlet of the pumps appears at the 2 times leaf frequency,and the pressure pulsation amplitude decreases.As the concentration of pig manure increases,the average flow increases,the volumetric efficiency,hydraulic efficiency increases,the flow pulsation decreases.The working performance when pumping non-Newtonian fluid is better than pumping water.Through this research can lay the foundation for the optimization design of the lobe rotor pump when transporting non-Newtonian fluids.