! ! linear_eos.f90 ! This file is part of ISOFT. ! ! Copyright 2016 Chris MacMackin <cmacmackin@gmail.com> ! ! This program is free software; you can redistribute it and/or modify ! it under the terms of the GNU General Public License as published by ! the Free Software Foundation; either version 2 of the License, or ! (at your option) any later version. ! ! This program is distributed in the hope that it will be useful, ! but WITHOUT ANY WARRANTY; without even the implied warranty of ! MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the ! GNU General Public License for more details. ! ! You should have received a copy of the GNU General Public License ! along with this program; if not, write to the Free Software ! Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, ! MA 02110-1301, USA. ! #ifdef DEBUG #define pure #define elemental #endif module linear_eos_mod !* Author: Christopher MacMackin ! Date: April 2016 ! License: GPLv3 ! ! Provides an abstract derived type which can be subtyped in order to ! implement an equation of state. ! use iso_fortran_env, only: r8 => real64 use factual_mod, only: scalar_field, uniform_scalar_field use equation_of_state_mod, only: equation_of_state implicit none private real(r8), parameter :: absolute_zero = -273.15_r8 type, extends(equation_of_state), public :: linear_eos !* Author: Chris MacMackin ! Date: April 2016 ! ! A linearised implementation of the equation of state, of the ! form $$ \rho = \rho_0[1-\beta_T(T-T_0) + \beta_S(S-S_0)]. $$ ! private real(r8) :: ref_rho = 1.0_r8 !! The density for the temperature and salinity about which the !! equation of state was linearised, \(\rho_0\). real(r8) :: ref_t = 0.0_r8 !! The temperature about which the equation of state was !! linearised, \(T_0\). real(r8) :: ref_s = 0.0_r8 !! The salinity about which the equation of state was !! linearised, \(S_0\). real(r8) :: beta_t = 0.0_r8 !! The thermal contraction coefficient, \(\beta_T\). real(r8) :: beta_s = 1.0_r8 !! The haline contraction coefficient, \(\beta_S\). contains procedure :: water_density => linear_water_density procedure :: water_density_derivative => linear_water_deriv procedure :: haline_contraction => linear_haline_contraction procedure :: thermal_contraction => linear_thermal_contraction end type linear_eos interface linear_eos module procedure constructor end interface linear_eos contains pure function constructor(ref_rho, ref_t, ref_s, beta_t, beta_s) result(this) real(r8), intent(in) :: ref_rho !! The density for the temperature and salinity about which the !! equation of state was linearised, \(\rho_0\). real(r8), intent(in) :: ref_t !! The temperature about which the equation of state was !! linearised, \(T_0\). real(r8), intent(in) :: ref_s !! The salinity about which the equation of state was !! linearised, \(S_0\). real(r8), intent(in) :: beta_t !! The thermal contraction coefficient, \(\beta_T\). real(r8), intent(in) :: beta_s !! The haline contraction coefficient, \(\beta_S\). type(linear_eos) :: this this%ref_rho = ref_rho this%ref_t = ref_t this%ref_s = ref_s this%beta_t = beta_t this%beta_s = beta_s end function constructor function linear_water_density(this, temperature, salinity) result(density) !* Author: Chris MacMackin ! Date: November 2016 ! ! Calculates the density of the water from the temperature and ! salinity, using a linear equatino of state, $$ \rho = ! \rho_0[1-\beta_T(T-T_0) + \beta_S(S-S_0)]. $$ class(linear_eos), intent(in) :: this class(scalar_field), intent(in) :: temperature !! A field containing the temperature of the water class(scalar_field), intent(in) :: salinity !! A field containing the salinity of the water class(scalar_field), pointer :: density !! A field containing the density of the water call temperature%guard_temp(); call salinity%guard_temp() call salinity%allocate_scalar_field(density) density = this%ref_rho * (1.0_r8 - this%beta_t*(temperature - this%ref_t) & + this%beta_s*(salinity - this%ref_s)) call temperature%clean_temp(); call salinity%clean_temp() call density%set_temp() end function linear_water_density function linear_water_deriv(this, temperature, d_temperature, salinity, & d_salinity, dir) result(d_density) !* Author: Chris MacMackin ! Date: November 2016 ! ! Calculates the derivative of the water density from the ! temperature and salinity, using a linear equatino of state, $$ ! \rho = \rho_0[1-\beta_T(T-T_0) + \beta_S(S-S_0)]. $$ class(linear_eos), intent(in) :: this class(scalar_field), intent(in) :: temperature !! A field containing the temperature of the water class(scalar_field), intent(in) :: d_temperature !! A field containing the derivative of the temperature of the !! water, in teh same direction as `dir` class(scalar_field), intent(in) :: salinity !! A field containing the salinity of the water class(scalar_field), intent(in) :: d_salinity !! A field containing the derivative of the salinity of the !! water, in the same direction as `dir` integer, intent(in) :: dir !! The direction in which to take the derivative class(scalar_field), pointer :: d_density !! A field containing the density of the water call temperature%guard_temp(); call salinity%guard_temp() call d_temperature%guard_temp(); call d_salinity%guard_temp() call salinity%allocate_scalar_field(d_density) d_density = this%ref_rho*(this%beta_s*d_salinity - this%beta_t*d_temperature) call temperature%clean_temp(); call salinity%clean_temp() call d_temperature%clean_temp(); call d_salinity%clean_temp() call d_density%set_temp() end function linear_water_deriv function linear_haline_contraction(this, temperature, salinity) result(coef) !* Author: Chris MacMackin ! Date: June 2017 ! ! Returns the haline contraction coefficient. ! class(linear_eos), intent(in) :: this class(scalar_field), intent(in) :: temperature class(scalar_field), intent(in) :: salinity class(scalar_field), allocatable :: coef allocate(uniform_scalar_field :: coef) coef = uniform_scalar_field(this%ref_rho*this%beta_s) end function linear_haline_contraction function linear_thermal_contraction(this, temperature, salinity) result(coef) !* Author: Chris MacMackin ! Date: June 2017 ! ! Returns the thermal contraction coefficient. ! class(linear_eos), intent(in) :: this class(scalar_field), intent(in) :: temperature class(scalar_field), intent(in) :: salinity class(scalar_field), allocatable :: coef allocate(uniform_scalar_field :: coef) coef = uniform_scalar_field(this%ref_rho*this%beta_t) end function linear_thermal_contraction end module linear_eos_mod