Added new constraint to check D/T ratio is equal to 1, subject to f_t…

…ritium being ixc
ukaea · Feb 19, 2025 · 66ddf99 · 66ddf99
1 parent 2519e60
commit 66ddf99
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Showing 2 changed files with 36 additions and 4 deletions.
diff --git a/source/fortran/constraint_equations.f90 b/source/fortran/constraint_equations.f90
@@ -286,6 +286,8 @@ subroutine constraint_eqns(m,ieqn,cc,con,err,symbol,units)
         case (90); call constraint_eqn_090(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
          ! Constraint for indication of ECRH ignitability
         case (91); call constraint_eqn_091(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
+         ! Constraint for D/T ratio
+        case (92); call constraint_eqn_092(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
        case default
 
         idiags(1) = icc(i)
@@ -3387,6 +3389,32 @@ subroutine constraint_eqn_091(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
       tmp_units = 'MW'
    end subroutine constraint_eqn_091
 
+   subroutine constraint_eqn_092(tmp_cc, tmp_con, tmp_err, tmp_symbol, tmp_units)
+      !! Equation for checking is D/T ratio is consistent, and sums to 1.
+      !! author: G Turkington, UKAEA
+      !! args : output structure : residual error; constraint value;
+      !! residual error in physical units; output string; units string
+      !! f_deuterium : input : fraction of deuterium ions
+      !! f_tritium  : input : fraction of tritium ions
+      !! f_helium3  : input : fraction of helium-3 ions
+      use physics_variables, only: f_deuterium, f_tritium, f_helium3
+      implicit none
+      real(dp), intent(out) :: tmp_cc
+      real(dp), intent(out) :: tmp_con
+      real(dp), intent(out) :: tmp_err
+      character(len=1), intent(out) :: tmp_symbol
+      character(len=10), intent(out) :: tmp_units
+
+
+      ! Iterate over f_tritium and calculate f_deuterium
+      f_deuterium = 1.0D0 - (f_tritium + f_helium3)
+      tmp_cc = 1.0D0 - (f_deuterium + f_tritium + f_helium3)
+      tmp_con = 1.0D0
+      tmp_err = tmp_con * tmp_cc
+      tmp_symbol = '='
+      tmp_units = 'fraction'
+
+   end subroutine constraint_eqn_092
 
 
 end module constraints
diff --git a/source/fortran/numerics.f90 b/source/fortran/numerics.f90
@@ -19,7 +19,7 @@ module numerics
   integer, parameter :: ipnvars = 175
   !!  ipnvars FIX : total number of variables available for iteration
 
-  integer, parameter :: ipeqns = 91
+  integer, parameter :: ipeqns = 92
   !!  ipeqns  FIX : number of constraint equations available
 
   integer, parameter :: ipnfoms = 19
@@ -193,7 +193,9 @@ module numerics
   !!  <LI> (88) Constraint for TF coil strain absolute value
   !!  <LI> (89) Constraint for CS coil quench protection
   !!  <LI> (90) Lower Limit on number of stress load cycles for CS (itr 167 fncycle)
-  !!  <LI> (91) Checking if the design point is ECRH ignitable (itv 168 fecrh_ignition) </UL>
+  !!  <LI> (91) Checking if the design point is ECRH ignitable (itv 168 fecrh_ignition)
+  !!  <LI> (92) D/T/He3 ratio in fuel sums to 1 </UL>
+
 
   integer, dimension(ipnvars) :: ixc
   !!  ixc(ipnvars) /0/ :
@@ -374,7 +376,7 @@ module numerics
   !! <LI> (170) beta_div : field line angle wrt divertor target plate (degrees)
   !! <LI> (171) casths_fraction : TF side case thickness as fraction of toridal case thickness
   !! <LI> (172) casths : TF side case thickness [m]
-  !! <LI> (173) EMPTY : Description
+  !! <LI> (173) f_deuterium : Deutterium fraction in fuel
   !! <LI> (174) EMPTY : Description
   !! <LI> (175) EMPTY : Description
   ! Issue 287 iteration variables are now defined in module define_iteration_variables in iteration variables.f90
@@ -545,7 +547,9 @@ subroutine init_numerics()
       'TF coil strain absolute value    ', &
       'CS current/copper area < Max     ', &
       'CS stress load cycles            ', &
-      'ECRH ignitability                '  &
+      'ECRH ignitability                ', &
+      'D/T ratio = 1                        ' &
+
       /)
 
     ! Please note: All strings between '...' above must be exactly 33 chars long