Source: NASA.Īn accurate empirical expression for the density-salinity-temperature relationship for coastal waters has been derived by Fonofoff and Millard (1983 ). Salinity-temperature dependence of seawater densityįig. Because of the primary focus of the Coastal Wiki on coastal waters, the dependency on pressure will be ignored in this article. Pressure only plays a role at depths much greater than those of coastal waters. The seawater density \rho in the ocean mainly depends on salinity S, temperature T and pressure p. Knowledge of the seawater density is therefore prerequisite for understanding and modelling marine processes. The same holds for the small-scale turbulent velocity fluctuations that are responsible for mixing processes in oceans, shelf seas and estuaries. The large-scale long-term mean currents in the ocean and in estuaries largely depend on the density differences between water masses. 3 Processes induced by density differencesĭensity gradients play a prominent role in marine hydrodynamics.2 Salinity-temperature dependence of seawater density.Lienhard V, "Surface tension of seawater," J. This data was correlated with an average absolute percentage deviation between measurements and the correlation of 0.19% and a maximum deviation of 0.60%. The uncertainty of the measurements varied from 0.18 to 0.37 mN/m with the average uncertainty being 0.22 mN/m. They published reference data for the surface tension of seawater over the salinity range of 20 - 131 g/kg and a temperature range of 1 - 92 degC at atmospheric pressure. The surface tension correlation used in this package is based on Nayar et al. The default values are T ds = 25 ☌, S ds = 35 g/kg, and P ds = 0.101325 MPa * T ds, S ds, and P ds are the dead state temperature, salinity, and pressure. Thermal conductivity (pressure dep.) (W/m-K)
SW_FlowExergy(T, S, P, T ds, S ds, P ds) * Isothermal compressibility of seawater (1/MPa)
MATLAB, EES, and VBA files in a zip archive (Version: 20 February 2017.Tables of properties in pdf format (Version: 9 December 2023).( PDF file which includes corrections through November 2023.) Zubair, "Thermophysical properties of seawater: A review of existing correlations and data," Desalination and Water Treatment, Vol. Lienhard V, "Thermophysical properties of seawater: A review and new correlations that include pressure dependence," Desalination, Vol. While the seawater properties library routines are freely distributed, it is requested that users of this library please cite the following two journal articles which comprehensively present how correlations in the library were developed, the original data sources, the validity ranges, and the uncertainty in each property function. See the file sw_copy.m or sw_copy.txt for conditions of use and license. This software is provided "as is" without warranty of any kind. They will run on all computers that support MATLAB, EES, or VBA. They are a self-contained library and are extremely easy to use. The seawater properties library routines are available in MATLAB, EES, and Excel VBA.
Where P 0 is taken as atmospheric pressure (0.101325 MPa) up to 100 ☌ and as the vapor pressure of seawater for higher temperatures. For select functions such as transport and colligative properties, the temperature and salinity also implicitly define the pressure as: For thermodynamic functions, the pressure dependence across 0 - 12 MPa has been incorporated. Some functions are valid only near atmospheric pressures while others are valid for a pressure range of 0 - 12 MPa. The temperature and salinity ranges are 0 - 120 ☌ and 0 - 120 g/kg respectively. They are given as functions of temperature, pressure, and salinity. The properties given by these codes are those needed for design of thermal and membrane desalination processes. This page provides tables and a library of computational routines for the thermophysical properties of seawater. Tables version: 9 December 2023 Description |