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利用稳态剪切实验和小振幅动态震荡剪切实验得到部分水解聚丙烯酰胺(HPAM)溶液的弹性模量、黏性模量、表观黏度和第一法向应力差,采用定义平均标准偏差为目标函数,拟合了HPAM溶液的松弛时间谱,结合KBKZ本构方程,在准确可靠表征HPAM溶液黏弹性的前提下,将松弛时间谱的个数减少为3个,并对比了实验值和模型计算值。实验结果表明,角频率变化对HPAM溶液弹性模量的影响较大而对其黏性模量的影响较小。HPAM溶液具有剪切稀化特性,且剪切速率越大,溶液弹性越大。选取6个松弛时间数和3个松弛时间数计算得到的黏性模量、表观黏度和第一法向应力差与实验数据基本一致。对于一般的HPAM溶液松弛时间谱的模拟计算,选取3个松弛时间数足以满足需要,为工程中的简化计算提供了理论依据。
The elastic modulus, viscous modulus, apparent viscosity and the first normal stress difference of partially hydrolyzed polyacrylamide (HPAM) solution were obtained by steady-state shear experiments and small-amplitude dynamic oscillatory shearing experiments. The average standard deviation As the objective function, the relaxation time spectrum of HPAM solution was fitted, and KBKZ constitutive equation was used to reduce the number of relaxation time spectrum to three under the premise of accurate and reliable characterization of the viscoelasticity of HPAM solution. The experimental values and Model calculated value. The experimental results show that the change of angular frequency has a great influence on the elastic modulus of HPAM solution and has little effect on the viscous modulus. HPAM solution has shear thinning characteristics, and the greater the shear rate, the greater the solution flexibility. The viscous modulus, apparent viscosity and the first normal stress difference calculated from the six relaxation times and the three relaxation times are basically consistent with the experimental data. For the general simulation calculation of relaxation time spectrum of HPAM solution, choosing 3 relaxation times is enough to meet the need, which provides a theoretical basis for simplified calculation in engineering.