不同质量分数NaCl和温度对黄原胶减阻特性影响的试验研究

为研究NaCl环境中黄原胶的减阻特性及温度对其性能的影响,通过在光滑圆管内进行不同质量分数NaCl的黄原胶溶液减阻特性试验,得到不同质量分数XG/NaCl溶液的减阻率随流动雷诺数的变化关系,并与黄原胶水溶液的减阻特性进行了对比.结果表明:黄原胶稀溶液(0.01%~0.02%)内,NaCl质量分数对溶液减阻率随雷诺数变化的影响较大,对黄原胶浓溶液(0.05%~0.06%)影响较小;高质量分数NaCl条件下,黄原胶质量分数低于0.03%时大致遵循B型减阻类型;当黄原胶溶液质量分数大于或等于0.03%时,溶液具有从低雷诺数下A型减阻到高雷诺数下B型减阻的转换特征;黄原胶溶液的减阻率在低雷诺数时对温度的变化较为敏感,高雷诺数下的减阻效果受温度影响较小.

Experimental study on effect of different NaCl concentrations and temperature on drag reduction characteristics of Xanthan gum

In order to investigate the drag reduction characteristics of xanthan gum(XG)in NaCl environment and the influence of temperature on the drag reduction performance, the drag reduction cha-racteristics test of xanthan gum solution with different concentrations of NaCl was carried out in a DN20 pipe made of transparent acrylic tube. For different mass fractions of XG solution with NaCl addition(XG/NaCl solution), the relation between the drag reduction efficiency and flow Reynolds number(Re)was obtained and compared with the drag reduction characteristics of XG solution. The result show that in dilute XG solution(0.01%-0.02%), the NaCl concentration has a greater influence on drag reduction rate with different Re, but has less influence on concentrated xanthan solution(0.05%-0.06%). In high NaCl concentration, the drag reduction type B is generally followed when the concentration of XG solution is lower than 0.03%. When the concentration of XG solution is greater than or equal to 0.03%, the solution has the conversion characteristics from type A drag reduction at low Re to type B drag reduction at high Re. The drag reduction rate of XG solution is sensitive to temperature change at low Re, while the drag reduction rate at high Re is less affected by temperature.