Engineering Mechanics

Proceedings Vol. 10 (2004)

ENGINEERING MECHANICS 2004

Copyright © 2004 Institute of Thermomechanics, Academy of Sciences of the Czech Republic, Prague

 

Hrubý J.
pages 121 - +10p., full text

A thermodynamic model of liquid and amorphous phases of water developed. Water is considered as a mixture of a low density structure (LDS) and a high density structure (HDS). When temperature or pressure are decreased, increasing number of water molecules participate in the LDS, assumed to resemble, on the local scale, the Ih or Ic ices. This explains the anomaly in density and heat capacity. Mathematically, the model comprises several algebraic relations containing a number of parameters, determined by fitting the measured thermodynamic properties of stable, supercooled, and superheated water. The model predicts that below approx. 223 K liquid water can exist in two distinct phases. At 77 K, the model predicts the densities of the so-called low density amorphous ice and high density amorphous ice with a good accuracy. On the same basis a model for surface tension of supercooled water was developed, reproducing the observed anomaly near 267 K.

Text and facts may be copied and used freely, but credit should be given to these Proceedings.

All papers were reviewed by members of the scientific committee.