function OutsideValue=DefineOutsideValues(UserVar,CtrlVar,MUA,F,OutsideValue)

OutsideValue=DefineOutsideValues(UserVar,CtrlVar,MUA,F,OutsideValue)

Defines values outside of a previous computational domain.

These values are used in a transient run when mapping (interpolating/extrapolating) from one mesh to another whenever some nodes of the new mesh are outside of the previous mesh. That is, when the new mesh has some nodes that are not witin any of the elements of the previous mesh.

This situation can arise when using, for example, manual deactivation of elements. If the domain increases in size, then some intial velocites and thicknesses must be defined over these new areas.

Typically, some minimum thickness will be defined over the new areas and the velocites set to zero. The velocity values are only used as a start values for a diagnostic uv solution. Hence, the exact velocites prescibed are not important (provided the uv solution converges). However, the thickness prescibed over the new areas is important as it defines the new start values over any outside areas. Note that in a diagnostic (time-independent run) the thickness is always prescribed using DefineGeometry.m. For that reason this routine is never used in a diagnostic run.

Only return scalar values.

% Prescribe here outside thickness values of twice the minimum ice thickness.
OutsideValue.h=2*CtrlVar.ThickMin ;

% Make sure the s and b correspondes to flotation. However this is not essential
% as s and b are always adjusted internally based on h, S and B given rho and
% rhow.
OutsideValue.s=mean(F.S)+OutsideValue.h*(1-mean(F.rho)/F.rhow);
OutsideValue.b=OutsideValue.s-OutsideValue.h;

% Define reasonably initial values for velocities for the uv solver. These
% values will have no impact on the final solution (provided the non-linear uv
% solver converges using these initial estimates.).
OutsideValue.ub=0;
OutsideValue.vb=0;

OutsideValue.ud=0;
OutsideValue.vd=0;

% these rates are only needed for explicit estimates of velocities. Similarly to
% the uv values above, these exact values will have no impact on the solution
% (again provided the non-linear solver converges using these initial
% estimates.).
OutsideValue.dubdt=0;
OutsideValue.dvbdt=0;

OutsideValue.duddt=0;
OutsideValue.dvddt=0;

OutsideValue.dhdt=0;

end

Published with MATLAB® R2020a