J/A+A/643/A105 AQUA, H2O EOS for planetary models (Haldemann+, 2020)
AQUA: a Collection of H2O equations of state for planetary models.
Haldemann J., Alibert Y., Mordasini Ch., Benz W.
<Astron. Astrophys. 643, A105 (2020)>
=2020A&A...643A.105H 2020A&A...643A.105H (SIMBAD/NED BibCode)
ADC_Keywords: Atomic physics ; Models
Keywords: equation of state - planets and satellites: interiors -
methods: numerical
Abstract:
Water is one of the key chemical elements in planetary structure
modelling. Due to its complex phase diagram, equations of state cover
often only parts of the pressure - temperature space needed in
planetary modelling. We construct an equation of state of H2O
spanning a very wide range from 0.1Pa to 400TPa and 150K to 105K,
which can be used to model the interior of planets. We combine
equations of state valid in localised regions to form a continuous
equation of state spanning over said pressure and temperature range.
We provide tabulated values for the most important thermodynamic
quantities, i.e., density, adiabatic temperature gradient, entropy,
internal energy and bulk speed of sound of water over this pressure
and temperature range. For better usability we also calculated density
- temperature and density - internal energy grids. We discuss
further the impact of this equation of state on the mass radius
relation of planets compared to other popular equation of states like
ANEOS and QEOS. AQUA is a combination of existing equation of state
useful for planetary models. We show that AQUA is in most regions a
thermodynamic consistent description of water. At pressures above 10
GPa AQUA predicts systematic larger densities than ANEOS or QEOS. A
feature which was already present in a previously proposed equation of
state, which is the main underlying equation of this work. We show
that the choice of the equation of state can have a large impact on
the mass-radius relation, which highlights the importance of future
developments in the field of equation of states and regarding
experimental data of water at high pressures.
Description:
Tabulated equation of state data of water calculated on a pressure -
temperature, density - temperature and density internal energy grid.
The pressure - temperature grid spans from 0.1Pa to 400TPa in pressure
and 100K to 105K in temperature. The density - temperature grid
spans from 10-10kg/m3 to 105kg/m3 in density and 100K to
105K in temperature. The density - internal energy grid spans from
10-10kg/m3 to 105kg/m3 in density and 105J/kg to 4x109J/kg
in internal energy. All grids are spaced logarithmically.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
eos_pt.dat 155 328993 Equation of state on a pressure - temperature grid
(table B6)
eos_rhot.dat 155 451801 Equation of state on a density - temperature grid
(table B7)
eos_rhou.dat 155 691961 Equation of state on a density - internal energy
grid (table B8)
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Byte-by-byte Description of file: eos_pt.dat
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Bytes Format Units Label Explanations
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1- 14 E14.8 Pa Press Pressure (1093 x log spaced)
16- 29 E14.8 K Temp Temperature (301 x log spaced)
31- 44 E14.8 kg/m3 rho Density
46- 59 E14.8 --- ad-grad (dlog(T)/dlog(P))S
61- 75 E15.8 J/kg/K s Specific entropy
77- 91 E15.8 J/kg u Specific internal energy
93-106 E14.8 m/s w Bulk speed of sound
108-121 E14.8 kg/mol mmw Mean molecular weight
123-136 E14.8 --- fion Ionization fraction (Nelectrons/Ntot)
138-151 E14.8 --- fdissoc Dissociation fraction (1-NH2O/Ntot)
153-155 I3 --- Phase [-10/5] Phase ID (1)
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Note (1): Phase ID as follows:
-1 = ice-Ih
-2 = ice-II
-3 = ice-III
-5 = ice-V
-6 = ice-VI
-7 = ice-VII
-10 = ice-X
3 = vapor
4 = liquid
5 = supercritical + superionic
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Byte-by-byte Description of file: eos_rhot.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 E14.8 kg/m3 Dens Density (1501 x log spaced)
16- 29 E14.8 K Temp Temperature (301 x log spaced)
31- 44 E14.8 Pa Press Pressure
46- 59 E14.8 --- ad-grad (dlog(T)/dlog(P))S
61- 75 E15.8 J/kg/K s Specific entropy
77- 91 E15.8 J/kg u Specific internal energy
93-106 E14.8 m/s w Bulk speed of sound
108-121 E14.8 kg/mol mmw Mean molecular weight
123-136 E14.8 --- fion Ionization fraction (Nelectrons/Ntot)
138-151 E14.8 --- fdissoc Dissociation fraction (1-NH2O/Ntot)
153-155 I3 --- Phase [-67/5] Phase ID (G1)
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Byte-by-byte Description of file: eos_rhou.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 14 E14.8 kg/m3 Dens Density (1501 x log spaced)
16- 30 E15.8 J/kg u Specific internal energy (461 x log spaced)
32- 45 E14.8 Pa Press Pressure
47- 60 E14.8 K Temp Temperature
62- 75 E14.8 --- ad-grad (dlog(T)/dlog(P))S
77- 91 E15.8 J/kg/K s Specific entropy
93-106 E14.8 m/s w Bulk speed of sound
108-121 E14.8 kg/mol mmw Mean molecular weight
123-136 E14.8 --- fion Ionization fraction (Nelectrons/Ntot)
138-151 E14.8 --- fdissoc Dissociation fraction (1-NH2O/Ntot)
153-155 I3 --- Phase [-87/10]?=-99 Phase ID (G1)
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Global notes:
Note (G1): Phase ID as follows:
0 = vapor+ice
1 = vapor+liquid
2 = ice+liquid
3 = vapor
4 = liquid
5 = super-critical+superionic
-1 = ice-Ih
-2 = ice-II
-3 = ice-III
-5 = ice-V
-6 = ice-VI
-7 = ice-VII/X
-12 = ice-Ih+ice-II
-13 = ice-Ih+ice-III
-23 = ice-II+ice-III
-25 = ice-II+ice-V
-26 = ice-II+ice-VI
-35 = ice-III+ice-V
-36 = ice-III+ice-VI
-67 = ice-VI+ice-VII
-10 = ice-X+superionic
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Acknowledgements:
Jonas Haldemann, jonas.haldemann(at)space.unibe.ch
(End) Patricia Vannier [CDS] 30-Sep-2020