摘要
为了更准确、快速地计算3区水和水蒸气的物性。针对水和水蒸气IAPWS-IF97公式3区中最新公布的反推公式"IAPWS-IF97-505"和迭代算法。分别采用该反推公式和5种迭代算法,使用FORTRAN语言进行编程,对3区的函数v(p,T)的计算方法进行了研究。结果表明该反推公式很好地满足了计算精度和边界连续性的要求,但数据录入工作量巨大。牛顿迭代法相比于其它迭代算法具有迭代次数少、收敛速度快和精度高等优点。并且发现迭代初值的选取在很大程度上影响迭代过程是否收敛,讨论了牛顿迭代法中应如何选取迭代初始值。
In order to calculate the characteristics of water and steam with faster speed and higher precision, in this paper, the latest backward equation ＂IAPWS-IF97-S05＂ and five kinds of iteration algorithms were adapted to study the computation of the function v（p, T） for region 3, using the Fortran programming language. The research suggested that the backward equation can meet the requirement of calculation accuracy and boundary continuity greatly, but the work of data input was huge. Compared with other iteration algorithms, Newton iteration algorithm had the advantages of less iteration time, faster convergence speed and higher calculation accuracy. Then it was found that the iteration initial value did have a deep influence on the convergence and the method how to select iterative initial value in Newton iteration algorithm was discussed.
出处
《锅炉技术》
CAS
北大核心
2013年第5期17-21,74,共6页
Boiler Technology
关键词
水和水蒸气
反推公式
迭代算法
初始值
收敛
water and steam
backward equation
iteration algorithm
initial value
convergence
