低密度区二甲醚气相黏度的研究

采用振动盘黏度计对低密度区二甲醚的气相黏度进行了实验研究,温度范围为299～396 K、压力范围为0.1～1.2MPa,黏度测量的不确定度为±2.0%.利用实验数据,将摩擦理论与PR方程结合建立了二甲醚的黏度模型,黏度实验数据与模型的绝对平均偏差为0.40%,最大偏差为1.32%,可以满足工程应用.     

Transport properties of a binary mixture of CO₂-N₂ from the pair potential energy functions based on a semi-empirical inversion method

The potential energy surface of a CO 2 –N 2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. Ref. Data 19 1179 (1990)]. With the new invert potential, the transport properties of CO2–N2 mixture are presented in a temperature range from 273.15 K to 3273.15 K at low density by employing the Chapman–Enskog scheme and the Wang Chang–Uhlenbeck–de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.     

基于反转法的CO2-O2混合物导热系数预测

采用反转法获得了CO2-O2的新势能,通过迭代计算提高了势能精度,在此基础上,给出了新势能的碰撞积分和特征参数.利用新的势能参数,根据分子动力学理论与WCUB理论,预测了CO2-O2混合气体零密度时的导热系数,计算的温度范围为273.15～3273.15 K,结果与实验数据的绝对平均偏差和最大偏差分别为3.87%和4....     

稀有气体纯质热物理性质的预测

根据量子力学和分子运动学理论,采用稀有气体的ab initio势能,分别计算了氦-4、氖、氩、氪和氙纯质在低密度时的热物理性质,包括第二维里系数,热扩散系数和热扩散因子,计算的温度范围为50—5000 K.预测结果具有较高的精度,与采用经验势能的计算结果相比,本文结果更接近实验数据和REFPROP 8.0的标准值,为相关的科学研究和工程应用提供了所需的基础数据. 关键词： ab initio势能')" href="#">ab initio势能 稀有气体 热物理性质     

Transport properties of a binary mixture of CO2-N2 from the pair potential energy functions based on a semi-empirical inversion method

The potential energy snrface of a CO2-N2 mixture is determined by using an inversion method, together with a new collision integral correlation [J. Phys. Chem. R@ Data 19 1179 （1990）]. With the new invert potential, the transport properties of CO2-N2 mixture are presented in a temperature range front 273.15 K to 3273.15 K at low density by employing the Chapman-Enskog scheme and the Wang Chang-Uhlenbeck de Boer theory, consisting of a viscosity coefficient, a thermal conductivity coefficient, a binary diffusion coefficient, and a thermal diffusion factor. The accuracy of the predicted results is estimated to be 2% for viscosity, 5% for thermal conductivity, and 10% for binary diffusion coefficient.     

HFC类二元混合制冷剂气相黏度预测

根据Vesovic-Wakeham理论,预测了10种HFC类二元混合制冷剂的气相黏度,所研究的混合制冷剂包括R32/R125、R32/R134a、R32/R143a、R32/R152a、R125/R134a、R125/R143a、R125/R152a、R134a/R143a、R134a/R152a和R143a/R152a,温度范围为298.15～423.15 K,压力范围为0.1～8.85 MPa,结果表明,黏度预测值具有较高的精度,可以满足工程应用的实际要求。     

基于反转法的O2-CO2 输运性质预测

采用反转法计算得到了O₂-CO₂混合气体新的势能参数.在此基础上,根据分子动力学理论,计算了混合气体在零密度下的输运性质,包括黏度系数、热扩散系数和热扩散因子,计算的温度范围为273.15—3273.15 K.与实验值比较表明,计算结果可以满足实际工程应用.