Page 269 - Handbook Of Multiphase Flow Assurance

268 10. Research methods in flow assurance

FIG. 10.38 RDF oxygen-oxygen for SPC model and water at 298 K. ***, Narten and Lewy (1971), _ _ _, this work).

SPC model was proven to be adequate, a study of the melting point was performed. It was
determined that the ice lattice loses its structure (melts) at a temperature of 200 K (scaled
273 K) which is reported in the literature (Karim et al., 1990) when the dielectric function is
scaled by a factor of 1.535. The oxygen-oxygen RDF for the SPC water model at 220 K (scaled
298 K) is shown in Fig. 10.39 to provide a better agreement with experimental data (Narten
and Lewy, 1971) and an excellent fit to the more recent neutron diffraction data (Soper and
Phillips, 1986). These comparisons indicate that SPC water model is a good representation of
the structural properties of the real water.
Hydrogen bonded network of water
Determination of the water hydrogen bonding structure
Water molecules are hydrogen bonded to each other and form a three-dimensional net-
work of ring-like structures. An example of the water structure was shown in Fig. 10.35 as
first described by Rahman and Stillinger (1973). They used the ST2 four-point pair potential