减阻剂对变截面管流动阻力特性的研究  

Study on drag characteristics of drag reducer for variable cross-section pipes

作　　者：王侃宏 张悦 刘欢 乔华 Wang Kanhong;Zhang Yue;Liu Huan;Qiao Hua(School of Energy and Environmental Engineering,Hebei University of Engineering,Handan,056038,China)

机构地区：[1]河北工程大学能源与环境工程学院,河北邯郸056038

出　　处：《煤炭与化工》2019年第2期121-125,134,共6页Coal and Chemical Industry

摘　　要：为探索减阻剂对变截面管水流阻力特性的影响,使用季铵盐十六烷基三甲基溴化铵作减阻剂,实验测试了该减阻剂3个质量分数的水溶液通过管径比为1∶1.49的突扩的流动阻力。研究结果表明,上游DN10管在3个质量浓度为8×10^(-5)、1.4×10^(-4)和2×10^(-4)下的临界雷诺数分别约为20 000、30 000和34 000,相应的最大减阻率分别为70%、72%和74%;而对于下游DN15管在质量浓度为8×10^(-5)时对应的临界雷诺数约为28 000,对应的最大减阻率为70%。当上游管流动雷诺数<各质量浓度对应的临界雷诺数时,突扩局部实验阻力系数<牛顿流体的理论值;当上游管流动雷诺数超过临近雷诺数后逐渐失去减阻效果时,减阻突扩流的局部实验阻力系数开始增加且大于牛顿流体的理论值。In order to explore the effect of drag reducer on resistance characteristics flowing in a variable cross-section pipe,the resistance for three mass concentrations of drag-reducing solution flows in a sudden expanded pipe with a diameter ratio of 1∶1.49 was measured by using quaternary ammonium salt cetyltrimethyl ammonium bromide as drag reducer.The results show that the critical Reynolds numbers for upstream DN10 tube flow at three mass concentrations which are 8×10^-5、1.4×10^-4 and 2×10^-4 are about 20 000,30 000 and 34 000 respectively,and the corresponding maximum drag reduction rates are 70%,72% and 74% respectively.For downstream DN15 tube flow at 8×10^-5,the corresponding critical Reynolds numbers are about 28 000,and the corresponding maximum drag reduction rate are 70%.For each mass concentration,as the Reynolds number of the upstream pipe flow is less than the critical Reynolds number,the sudden expansion drag coefficient is smaller than the theoretically predicted value of Newtonian fluids and increases with Reynolds number.While as the Reynolds number proceeds critical one,it is larger than that of Newton fluids and increases with increasing Reynolds numbers.

关 键 词：突扩 局部阻力 减阻率 雷诺数 

分 类 号：TQ021.1[化学工程]