A New Method for Optimizing the Computing Process of IAPWS-IF97

摘要

To improve the computing speed and accuracy of the latest IAPWS-IF97 (2007.8 Revision), by code optimization method, optimized the computing process of JAPWS-IF97. The key methods of optimizing the computing process of IAPWS-IF97 are merge constant values, refine algebra equations, delete common sub expressions, extract constant code out of cycle and weaken operation intensity. We need only use these methods to optimize the implementation of the basic equations, derivative equations and backward equations for regions 1, 2.3, the optimization rules are givea The most important optimization key method is using weaken operation intensity for theirs power operations. This paper mainly analyzed and tested the comparisons of computing time, accuracy and consistency before and after optimization in detail. After optimization, the results show that the operation count is more than 2.42 times decreased than before optimization on average, and the computing speed is more than 5.63 times faster than before optimization on average. The advantages are computing time faster, more accuracy and improved the consistency of the boundary of B23, Ts(p) and B2bc,ps (T).