油品粘度的计算求值法

使用本文介绍的关系式，只需测出油品某一温度下的粘度，即可计算出其他温度下的粘度；并将计算结果与其他方法计算得出的粘度进行了比较，证明该法公式简单，使用方便，计算值与实测值的误差远低于其他方法。     

应用马丁─侯状态方程计算含氨气体混合物的物性参数

本文将马丁—侯状态方程用于计算气体混合物的恒压热容、粘度和导热系数．含氨气体混合物的恒压热容为理想气体混合物热容与真实气体混合物剩余热容之和，根据剩余粘度法计算粘度，剩余导热系数法计算导热系数．三种压力，不同温度条件下气体混合物恒压热容、粘度和导热系数的计算结果表明：计算值与实验值相吻合．并分别拟合了合成氨生产三种工艺含氨气体混合物恒压热容、粘度、导热系数的计算式。     

关联沥青针入度和粘度的数学模型

以Robert的一种关联沥青针入度和粘度的数学模型为基础，对模型进行了修正。利用该模型可以通过已知针入度值计算相应温度下的粘度，或由粘度计算针入度值。模型检验表明，其误差较小，可用来求取沥青的感温性指标，如粘温指数或针入度指数等。     

含氨气体混合物的粘度和导热系数

本文讨论常压和加压下含氨气体混合物的粘度和导热系数的计算方法。常压下，改进的Ｓｕｔｈｅｒｌａｎｄ法计算粘度，Ｌｉｎｄｓａｙ－Ｂｒｏｍｌｅｙ法计算导热系数，其准确度较高。加压下，按Ｍ－Ｈ状态方程和Ｂ－Ｂ状态方程求得混合物的密度，采用剩余函数法计算了氨含量４．８％、１０．６％，压力９．９１ＭＰａ、１９．７２ＭＰａ、２９．５２ＭＰａ，不同温度下气体混合物的粘度和导热系数，计算结果与加压下含氨气体混合物粘度和导热系数的实验测定值相吻合。     

橡胶增塑剂A1220的运动粘度-温度特性研究

研究橡胶增塑剂A1220运动粘度-温度特性,推算橡胶增塑剂A1220在不同温度下的运动粘度。用运动粘度测试值通过拟合和经验式计算,得到拟合运动粘度-温度方程和经验式运动粘度-温度方程,并将计算值与测试值进行对比。结果表明:橡胶增塑剂A1220在100～160℃内的拟合方程计算的运动粘度准确度较高,在180～200℃内的经验式方程计算的运动粘度准确度较高。     

CO2-原油体系粘度及其预测模型的研究

通过实验和模型计算,研究了CO2-原油体系粘度的影响因素以及相应规律.在相同含水率、CO2注入摩尔分数条件下,体系的黏度随着温度的升高而降低.在一定温度下,压力高于泡点压力时,粘度随压力的减小而减小;压力低于泡点压力时,粘度随压力的减小而增加.油样的粘度计算结果符合相对粘度与CO2注入摩尔分数呈线性关系.与现有的粘度计算模型相比,改进的PR模型考虑的因素更加全面,计算精度更高,可以用于CO2-原油体系粘度的计算.     

应用ANFIS预测混炼胶粘度

混炼胶粘度是影响混炼胶后序加工过程的员重要的因素之一，同时也是影响橡胶制品质量的重要因素，因此，根据混炼胶的粘度来控制泥炼过程是非常必要的。但由于混炼胶的粘度在线测量难度大，通过建立有效的预测模型，采用计算的方法来预测混炼胶的粘度是一种行之有效的方法。首次探讨了通过应用自适应模糊推理系统(ANFIS)来建立混炼胶粘度的预测模型，并根据已有的实验数据预测了混炼胶粘度，达到了较高的预测精度。     

聚丙烯腈—硫氢酸钠水溶液的流变方程

测定了聚丙烯腈－友氟酸钠水溶液在不同浓度下的流变性能，分别建立了剪切速率、温度、浓度与粘度的关系，进一步得以剪切速率、温度、浓度为自为量的粘度关联式，将关联式应用于浓度的计算，计算与实验值误差小于2％。     

复合共挤出喂料块三维流动分析

利用美国FLUENT公司研究开发的Polyflow软件，针对带喂料块共挤出机头中共挤出喂料块内的流动进行了分析。首先从理论上分析，创建几何模型，列出控制方程，给出边界条件；然后利用三维有限元方法来求解上述已列出的方程，得出计算结果；最后计算结果分粘度相同和粘度不同的物料复合挤出进行比较分析，得出结论，即多层高聚物熔体的粘度比和流率比会对喂料块内复合挤出流动的界面形状有显著影响。     

二甲基硅油粘度调合计算方法

叙述了生产二甲基硅油过程中粘度调合的计算方法。介绍了三种计算方法,通过与实际值对比得出最优的计算方法。结果表明,当组分间粘度相差不大时,三种计算方法的结果与实测值相近;而当组分间粘度相差较大时,使用对数分率法计算结果更佳。对二甲基硅油生产粘度的调合具有实际的指导意义。     

非电解质水溶液黏度的关联

许多化工过程的设计需要估算含水体系的黏度,但目前的黏度关联方法用于含水体系时误差较大.今以作者所在课题组近期提出的非水液体混合物黏度关联方程为基础,通过引入形状因子,得出了一个非电解质水溶液的黏度方程.该方程可用于二元非电解质水溶液黏度的关联,且能利用二元黏度得到的关联参数推算三元非电解质水溶液的黏度.该方程对54个二元非电解质水溶液体系黏度(总计2876个黏度数据点)关联的总平均相对偏差为4.60%;对7个三元非电解质水溶液体系黏度(总计352个黏度数据点)推算的总平均相对偏差为3.75%.结果表明,该方程具有较高的关联精度和推算精度.     

An equation suitable for describing the viscosity of dilute to moderately concentrated polymer solutions

It is shown that an equation first derived for describing the Newtonian viscosity of suspensions of rigid spheres is also applicable for describing the Newtonian viscosity of dilute to moderately concentrated polymer solutions. The equation is applicable for relative viscosities from 1 to about 100. In addition, it is possible to rearrange the equation so that the intrinsic viscosity is expressible as an explicit function of the other variables. This leads to a very convenient method of calculating the intrinsic viscosity from a determination of the relative viscosity at a single polymer concentration.     

Rheological behavior of polymer melts with natural fibers

Flow behavior of polymer liquids filled with short fibers (particulate fillers) was theoretically analyzed from the point of view of the free volume theory. Assuming that the filler addition changes the occupied volume, while the temperature variations cause mainly the free volume changes, a general expression describing the viscosity of the system as a function of the filter content, temperature variations, and rheological properties of the pure polymer liquid was derived. If the viscosity curve of the unfilled polymer is described by the Carreau equation, the corresponding viscosity curve of the filled polymer is also represented by an equation of Carreau type. However, this equation has other values of Newtonian viscosity and the power exponent in comparison with the initial equation. Both parameters depend on the filler content and temperature. The derived equation predicts a viscosity rise and a stronger non‐Newtonian behavior of the system with increasing filler content. The temperature rise exerts an opposite effect on the rheological behavior. The theoretical predictions are in good accordance with viscosity measurements for low‐density polyethylene and polystyrene melts filled with short cotton, flax, and hemp fibers. © 2005 Wiley Periodicals, Inc. J Appl Polym Sci 97: 1401–1409, 2005     

Prediction of elongation viscosity of polymer melts

Melt extension flow is a common flow pattern during polymer processing, such as entrance converging flow in die extrusion or runner injection of polymer melts from an extruder barrel, blow molding, blowing film and melt spinning. Extensional viscosity is one of the important characterizations of the flow characteristics for polymer fluids. A new extension viscosity equation was established based on White‐Metzner model, Vinogradov‐Malkin viscosity equation and a new relaxation time equation in the present paper. The melt elongation viscosities of metallocene linear low‐density polyethylene (mLLDPE) and polyvinyl butyral (PVB) resins at 130°C were estimated applying this viscosity equation, and the predictions were compared with the measured data of mLLDPE and PVB resins at 130°C reported from reference. The results showed that calculations were close to the experimental data. The parameters in this equation were easy to be determined and the equation was convenient to use for estimating the extension viscosity of polymer melts. POLYM. ENG. SCI., 2010. © 2010 Society of Plastics Engineers     

氯化聚丙烯甲苯溶液的特性黏数及其黏均分子量

分别用乌氏黏度计和旋转黏度计测定了氯化聚丙烯甲苯溶液的特性黏数和黏度,把特性黏数和黏度进行关联,发现ηsp/C与浓度C(ml/g)的关系用多项式ηsp/C=[η]+k1[η]2C+k2[η]2C2拟合,可以得到很好的结果。并且用特性黏数和Mark-Houwink方程求出了不同氯化聚丙烯(CPP)的黏均分子量。     

浓缩湿法磷酸流变性的研究

测定了浓缩湿法磷酸的流变特性,研究了磷酸浓度、温度、不同杂质含量对磷酸黏度的影响;回归分析得到磷酸黏度、温度、浓度三者间的关系方程。研究表明,浓缩磷酸黏度、温度关系符合阿累尼乌斯方程;金属杂质中铝离子对黏度影响较大,管道输送料浆前应主要降低铝离子含量,且保持温度在60℃左右,以降低磷酸黏度,减少输送能耗。     

The effect of liquid viscosity on gas holdup in a vertical pipe

The effect of liquid viscosity on gas holdup in a 15.1 mm diameter vertical pipe was assessed over the viscosity range 0.00092-1.670 N s m-². Gas holdup increased with increased liquid viscosity. The sensitivity of holdup to changes in viscosity was slight at low viscosity but was markedly increased at higher viscosities. Gas holdup was found to be well described, over the viscosity range studied, by the empirical equation:      

Comments on the accuracy of zero shear intrinsic viscosity of high molecular weight polyacrylamide

The intrinsic viscosity of a polymer is traditionally measured with a capillary tube viscometer where the shear rate range is moderately high. Such method is valid when the polymers are non-ionic and have low to moderate molecular weight. The viscosity-shear rate curves obtained for dilute aqueous solutions of two high molecular weight polyacrylamides using two rotational viscometers indicate a strong shear-dependent viscosity in the medium to high shear rate regions. The zero shear intrinsic viscosity of the polymers determined by extrapolation from the high shear rate region to the zero shear condition may result in large errors. Its implication in predicting the molecular weight of polymers using the Mark-Houwink-Sakurada equation is discussed. A rheological equation for intrinsic viscosity as a function of shear rate is proposed.     

黏弹流体动态黏度数学模型与实验研究

针对经典Maxwell本构模型的局限性进行了相应的非线性修正,提出了一种新的黏弹本构模型,利用修正模型和基于黏性耗散机理建立的黏滞动力方程,得到了振动剪切流场黏弹流体的动态黏度函数.通过将动态黏度函数应用于简单振动剪切流,得到了与传统计算方法相一致的结果.最后,进行了同轴圆筒动态流变实验.实验数据与垂直叠加振动剪切流场中LDPE熔体黏度的理论值进行了对比,发现动态黏度函数在小振幅范围内具有较好的预测能力.