StabFem Demo script for concentric jets WITH CONSTANT PROFILE.

Here we set Umax,2 = 1 for the outer jet and Umax,1 = 3/4 so that the ratio of MEAN VELOCITIES is the same as in the case of Poiseulle profile with Umax =1 for each jet

The arclength continuation is done in the plane (Re,beta) where beta is the "monitor" defined as beta = 100*int( ur* exp(-(x-2)^2 ). you can also use the energy as a monitor. For this just remove customized definitions of beta and dbetadu in SF_Custom.idp, the solver will switch to default ones.

NB :

- Using new generic interface - postprocessing is done completely from database exploration

Contents

Chapter 0 : Initialization

close all;
addpath([fileparts(fileparts(pwd)), '/SOURCES_MATLAB']);
SF_Start('verbosity',4,'ffdatadir','./WORK_ArcLength_Constant/'); % NB use verbosity=2 for autopublish mode ; 4 during work
% SF_core_arborescence('cleanall'); % uncomment this line to clean database
SF_core_setopt('ErrorIfDiverge',false); % recommended option when using continuation mode
set(groot, 'defaultAxesTickLabelInterpreter','latex');
set(groot, 'defaultLegendInterpreter','latex');
NOTICE  - Initialization already done
WARNING - Detected verbosity = 4 in Publish mode ; not recommended ! switching to 2 instead

Chapter 1 : Generate a mesh and initial base flow

Parameters

U1Max= 3/4.; % to have same ratio of mean velocities as for Poiseuille case
U2Max=1.;    % set to 1
R1=0.5; distance=4.5; D2=1; Lpipe = 0.01;
Xmax = 100;
YMax = 20;
bctype = 0; % select 0 for constant and 1 for Poiseuille and 2 for Tanh
% Mesh generation
paramMESH = [R1 distance D2 Lpipe Xmax YMax];
ffmesh = SF_Mesh('Mesh_ConcentricJets_Pipes.edp','params',paramMESH,'cleanworkdir','yes');
figure;subplot(2,1,1);SF_Plot(ffmesh,'mesh','title','Initial mesh');
subplot(2,1,2);SF_Plot(ffmesh,'mesh','title','Initial mesh','xlim',[-2 2],'ylim',[0 2]);

% Generation of an initial solution
bf = SF_BaseFlow(ffmesh,'Re',1,'bctype',bctype,'U1',U1Max,'U2',U2Max,'solver','Newton_Axi.edp');


% Adapt
%bf = SF_Adapt(bf,'anisomax',3,'nbjacoby',3);
% plots
%figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8]);
%Xpos = 1; Y=[0:0.01:1.5];
%uxline=SF_ExtractData(bf,'ux',Xpos,Y);
%figure; plot(uxline,Y);xlabel('Ux(r,1)');ylabel('r');title('axial velocity at location x=1');
WARNING -  Your program uses depreciated syntax 'Params' to pass parameters 
WARNING -  It is advised to switch to new method using 'Options', and modify your Freefem solvers to detect parameters using 'getARGV'  
WARNING -  Folder ./WORK_ArcLength_Constant/MESHBF not found : creating it !

loop with increasing Re

Increasing Reynolds in a structured manner

ReTab = [10,30,50,55,60,65];
for Re = ReTab
    bf = SF_BaseFlow(bf,'Re',Re);
    [bf] = SF_Adapt(bf,'anisomax',3,'nbjacoby',10,'Hmax',2);
%    [bf] = SF_Adapt(bf,'anisomax',3,'nbjacoby',10,'Hmax',5);
end

plot last BF after this stage

figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8],'title',['Re = ',num2str(bf.Re),'; E = ',num2str(bf.Energy)] );
hold on;  SF_Plot(bf,'psi','contour','only','xlim',[-1 12],'ylim',[0 8],'Clevels',[ - 1:.1:-.1, 0:.01:.0625,.1,.2, .5:.5:10]);

figure;subplot(2,1,1);SF_Plot(bf.mesh,'mesh','title','Adapted mesh');
subplot(2,1,2);SF_Plot(bf.mesh,'mesh','title','Initial mesh','xlim',[-2 2],'ylim',[0 2]);
WARNING -  Error in SF_Plot : Field psi does not exist

Test Arclength

 bf = SF_BFContinue(bf,'step',0.001,'solver','ArcLengthContinuationAxi.edp');
% note that the first step is still backwards and I don't understand why !!!

Arclength continuation loop

Re = bf.Re;
ReMax = 80; ReMin = 25; % this is the termination of the loop. Remin is in case the curve does not loop back.
stepMax = 2;
step = stepMax;
%EnerList = []; betaList = []; ReList = []; // NOW USELESS IF USING DATABASE !

while ( bf.Re < ReMax && bf.Re > ReMin && step > 1e-3)
    bf=SF_BFContinue(bf,'step',step,'solver','ArcLengthContinuationAxi.edp');
    if(bf.iter < 0)
        disp("Not converged. Arc-length step reduced by a factor 2");
        step = 0.5*step;
        bf = SF_BFContinue(bf,'step',step,'solver','ArcLengthContinuationAxi.edp');
         if(bf.iter < 0)
            disp("Not converged. Reducing again by a factor 10");
            step = 0.1*step;
            bf = SF_BFContinue(bf,'step',step,'solver','ArcLengthContinuationAxi.edp');
            if bf.iter<0
                disp('Arclength continuation failed')
                break
            end
         end
    end
    step = min(1.4*step,stepMax); % raise the step for next iteration
    Re = bf.Re;
    figure(45);plot(Re,bf.beta,'*'); pause(0.1); hold on;
end
echo 2 0.76578 0.6431 | /PRODCOM/Singularity/freefem++/v4.9-20220413/bin/FreeFem++-mpi -nw -v 0 ArcLengthContinuationAxi.edp  -U1 0.75 -U2 1 -bctype 0 -Symmetry S : Signal 73
WARNING - SF_core_freefem: Error while using FreeFem++  ; file = ArcLengthContinuationAxi.edp ; error code = 201 :  Your Newton iteration did not converge
WARNING - SF_BFcontinue computation did not converge
Not converged. Arc-length step reduced by a factor 2
echo 1 0.76578 0.6431 | /PRODCOM/Singularity/freefem++/v4.9-20220413/bin/FreeFem++-mpi -nw -v 0 ArcLengthContinuationAxi.edp  -U1 0.75 -U2 1 -bctype 0 -Symmetry S : Signal 73
WARNING - SF_core_freefem: Error while using FreeFem++  ; file = ArcLengthContinuationAxi.edp ; error code = 201 :  Your Newton iteration did not converge
WARNING - SF_BFcontinue computation did not converge
Not converged. Reducing again by a factor 10
echo 0.2744 0.95272 0.30386 | /PRODCOM/Singularity/freefem++/v4.9-20220413/bin/FreeFem++-mpi -nw -v 0 ArcLengthContinuationAxi.edp  -U1 0.75 -U2 1 -bctype 0 -Symmetry S : Signal 73
WARNING - SF_core_freefem: Error while using FreeFem++  ; file = ArcLengthContinuationAxi.edp ; error code = 201 :  Your Newton iteration did not converge
WARNING - SF_BFcontinue computation did not converge
Not converged. Arc-length step reduced by a factor 2

Generating the summary of Data Base for postprocessing

sfs = SF_Status;
################################################################################
...  SUMMARY OF YOUR DATABASE FOLDER :    ./WORK_ArcLength_Constant/
#################################################################################
 
.... CONTENT OF DIRECTORY ./WORK_ArcLength_Constant/MESHES :
     (list of meshes previously created/adapted ; couples of .msh/.ff2m files )
 
Index | Name              | generation mode | Date                 | Nv      
1     | FFMESH_000001.msh | initial         | 22-mars-2023 16:43:51 | 702     
2     | FFMESH_000002.msh | adapted         | 22-mars-2023 16:44:03 | 2465    
3     | FFMESH_000003.msh | adapted         | 22-mars-2023 16:44:19 | 3204    
4     | FFMESH_000004.msh | adapted         | 22-mars-2023 16:44:40 | 4235    
5     | FFMESH_000005.msh | adapted         | 22-mars-2023 16:45:01 | 5113    
6     | FFMESH_000006.msh | adapted         | 22-mars-2023 16:45:25 | 5835    
7     | FFMESH_000007.msh | adapted         | 22-mars-2023 16:45:52 | 5845    
 
#################################################################################
#################################################################################
 
.... CONTENT OF DIRECTORY ./WORK_ArcLength_Constant/BASEFLOWS
     (couples of .txt/.ff2m files )
 
 Index | Name              | Type         | Date                 | Mesh file         | Re         | beta       | Energy    
 1     | FFDATA_000001.txt | BaseFlow     | 22-mars-2023 16:43:55 | FFMESH_000001.msh | 1          | 3.8124     | 3.8124    
 2     | FFDATA_000002.txt | BaseFlow     | 22-mars-2023 16:44:02 | FFMESH_000001.msh | 10         | 18.5917    | 18.5917   
 3     | FFDATA_000003.txt | BaseFlow     | 22-mars-2023 16:44:17 | FFMESH_000002.msh | 30         | 106.998    | 106.998   
 4     | FFDATA_000004.txt | BaseFlow     | 22-mars-2023 16:44:38 | FFMESH_000003.msh | 50         | 154.689    | 154.689   
 5     | FFDATA_000005.txt | BaseFlow     | 22-mars-2023 16:44:58 | FFMESH_000004.msh | 55         | 164.412    | 164.412   
 6     | FFDATA_000006.txt | BaseFlow     | 22-mars-2023 16:45:23 | FFMESH_000005.msh | 60         | 171.999    | 171.999   
 7     | FFDATA_000007.txt | BaseFlow     | 22-mars-2023 16:45:50 | FFMESH_000006.msh | 65         | 178.162    | 178.162   
 8     | FFDATA_000008.txt | BaseFlow     | 22-mars-2023 16:46:34 | FFMESH_000007.msh | 64.9474    | 178.205    | 178.205   
 9     | FFDATA_000009.txt | BaseFlow     | 22-mars-2023 16:46:59 | FFMESH_000007.msh | 66.2246    | 179.736    | 179.736   
 10    | FFDATA_000010.txt | BaseFlow     | 22-mars-2023 16:47:22 | FFMESH_000007.msh | 67.5156    | 181.255    | 181.255   
 11    | FFDATA_000011.txt | BaseFlow     | 22-mars-2023 16:47:51 | FFMESH_000007.msh | 68.8181    | 182.765    | 182.765   
 12    | FFDATA_000012.txt | BaseFlow     | 22-mars-2023 16:48:22 | FFMESH_000007.msh | 70.1266    | 184.268    | 184.268   
 13    | FFDATA_000013.txt | BaseFlow     | 22-mars-2023 16:48:54 | FFMESH_000007.msh | 71.4252    | 185.777    | 185.777   
 14    | FFDATA_000014.txt | BaseFlow     | 22-mars-2023 16:49:31 | FFMESH_000007.msh | 72.611     | 187.37     | 187.37    
 15    | FFDATA_000015.txt | BaseFlow     | 22-mars-2023 16:53:05 | FFMESH_000007.msh | 72.6548    | 187.46     | 187.46    
 16    | FFDATA_000016.txt | BaseFlow     | 22-mars-2023 16:53:35 | FFMESH_000007.msh | 72.7057    | 187.59     | 187.59    
 17    | FFDATA_000017.txt | BaseFlow     | 22-mars-2023 16:54:06 | FFMESH_000007.msh | 72.7358    | 187.785    | 187.785   
 18    | FFDATA_000018.txt | BaseFlow     | 22-mars-2023 16:56:13 | FFMESH_000007.msh | 72.6877    | 187.917    | 187.917   
 19    | FFDATA_000019.txt | BaseFlow     | 22-mars-2023 16:56:46 | FFMESH_000007.msh | 72.5046    | 188.014    | 188.014   
 20    | FFDATA_000020.txt | BaseFlow     | 22-mars-2023 16:57:14 | FFMESH_000007.msh | 72.2322    | 188.018    | 188.018   
 21    | FFDATA_000021.txt | BaseFlow     | 22-mars-2023 16:57:45 | FFMESH_000007.msh | 71.8608    | 187.946    | 187.946   
 22    | FFDATA_000022.txt | BaseFlow     | 22-mars-2023 16:58:13 | FFMESH_000007.msh | 71.3572    | 187.784    | 187.784   
 23    | FFDATA_000023.txt | BaseFlow     | 22-mars-2023 16:58:45 | FFMESH_000007.msh | 70.6723    | 187.502    | 187.502   
 24    | FFDATA_000024.txt | BaseFlow     | 22-mars-2023 16:59:16 | FFMESH_000007.msh | 69.7366    | 187.053    | 187.053   
 25    | FFDATA_000025.txt | BaseFlow     | 22-mars-2023 16:59:47 | FFMESH_000007.msh | 68.4518    | 186.371    | 186.371   
 26    | FFDATA_000026.txt | BaseFlow     | 22-mars-2023 17:00:22 | FFMESH_000007.msh | 66.6976    | 185.378    | 185.378   
 27    | FFDATA_000027.txt | BaseFlow     | 22-mars-2023 17:00:57 | FFMESH_000007.msh | 64.9565    | 184.362    | 184.362   
 28    | FFDATA_000028.txt | BaseFlow     | 22-mars-2023 17:01:30 | FFMESH_000007.msh | 63.219     | 183.338    | 183.338   
 29    | FFDATA_000029.txt | BaseFlow     | 22-mars-2023 17:01:59 | FFMESH_000007.msh | 61.4794    | 182.317    | 182.317   
 30    | FFDATA_000030.txt | BaseFlow     | 22-mars-2023 17:02:30 | FFMESH_000007.msh | 59.7317    | 181.307    | 181.307   
 31    | FFDATA_000031.txt | BaseFlow     | 22-mars-2023 17:03:05 | FFMESH_000007.msh | 57.9677    | 180.324    | 180.324   
 32    | FFDATA_000032.txt | BaseFlow     | 22-mars-2023 17:03:41 | FFMESH_000007.msh | 56.1765    | 179.388    | 179.388   
 33    | FFDATA_000033.txt | BaseFlow     | 22-mars-2023 17:04:16 | FFMESH_000007.msh | 54.3444    | 178.53     | 178.53    
 34    | FFDATA_000034.txt | BaseFlow     | 22-mars-2023 17:04:53 | FFMESH_000007.msh | 52.4563    | 177.798    | 177.798   
 35    | FFDATA_000035.txt | BaseFlow     | 22-mars-2023 17:05:30 | FFMESH_000007.msh | 50.5015    | 177.263    | 177.263   
 36    | FFDATA_000036.txt | BaseFlow     | 22-mars-2023 17:06:01 | FFMESH_000007.msh | 48.4907    | 177.026    | 177.026   
 37    | FFDATA_000037.txt | BaseFlow     | 22-mars-2023 17:06:30 | FFMESH_000007.msh | 46.4833    | 177.191    | 177.191   
 38    | FFDATA_000038.txt | BaseFlow     | 22-mars-2023 17:07:04 | FFMESH_000007.msh | 44.5859    | 177.798    | 177.798   
 39    | FFDATA_000039.txt | BaseFlow     | 22-mars-2023 17:07:46 | FFMESH_000007.msh | 42.8819    | 178.785    | 178.785   
 40    | FFDATA_000040.txt | BaseFlow     | 22-mars-2023 17:08:33 | FFMESH_000007.msh | 41.3858    | 180.043    | 180.043   
 41    | FFDATA_000041.txt | BaseFlow     | 22-mars-2023 17:09:20 | FFMESH_000007.msh | 40.0726    | 181.486    | 181.486   
 42    | FFDATA_000042.txt | BaseFlow     | 22-mars-2023 17:10:06 | FFMESH_000007.msh | 38.9096    | 183.052    | 183.052   
 43    | FFDATA_000043.txt | BaseFlow     | 22-mars-2023 17:10:51 | FFMESH_000007.msh | 37.8682    | 184.706    | 184.706   
 44    | FFDATA_000044.txt | BaseFlow     | 22-mars-2023 17:11:29 | FFMESH_000007.msh | 36.926     | 186.421    | 186.421   
 45    | FFDATA_000045.txt | BaseFlow     | 22-mars-2023 17:12:09 | FFMESH_000007.msh | 36.0655    | 188.182    | 188.182   
 46    | FFDATA_000046.txt | BaseFlow     | 22-mars-2023 17:12:51 | FFMESH_000007.msh | 35.2734    | 189.978    | 189.978   
 47    | FFDATA_000047.txt | BaseFlow     | 22-mars-2023 17:13:31 | FFMESH_000007.msh | 34.5394    | 191.802    | 191.802   
 48    | FFDATA_000048.txt | BaseFlow     | 22-mars-2023 17:14:13 | FFMESH_000007.msh | 33.8552    | 193.647    | 193.647   
 49    | FFDATA_000049.txt | BaseFlow     | 22-mars-2023 17:14:56 | FFMESH_000007.msh | 33.2144    | 195.51     | 195.51    
 50    | FFDATA_000050.txt | BaseFlow     | 22-mars-2023 17:15:35 | FFMESH_000007.msh | 32.6117    | 197.387    | 197.387   
 51    | FFDATA_000051.txt | BaseFlow     | 22-mars-2023 17:16:14 | FFMESH_000007.msh | 32.0426    | 199.277    | 199.277   
 52    | FFDATA_000052.txt | BaseFlow     | 22-mars-2023 17:16:52 | FFMESH_000007.msh | 31.5037    | 201.176    | 201.176   
 53    | FFDATA_000053.txt | BaseFlow     | 22-mars-2023 17:17:32 | FFMESH_000007.msh | 30.9919    | 203.085    | 203.085   
 54    | FFDATA_000054.txt | BaseFlow     | 22-mars-2023 17:18:14 | FFMESH_000007.msh | 30.5046    | 205.001    | 205.001   
 55    | FFDATA_000055.txt | BaseFlow     | 22-mars-2023 17:18:54 | FFMESH_000007.msh | 30.0397    | 206.924    | 206.924   
 56    | FFDATA_000056.txt | BaseFlow     | 22-mars-2023 17:19:31 | FFMESH_000007.msh | 29.5952    | 208.853    | 208.853   
 57    | FFDATA_000057.txt | BaseFlow     | 22-mars-2023 17:20:08 | FFMESH_000007.msh | 29.1696    | 210.786    | 210.786   
 58    | FFDATA_000058.txt | BaseFlow     | 22-mars-2023 17:20:41 | FFMESH_000007.msh | 28.7613    | 212.725    | 212.725   
 59    | FFDATA_000059.txt | BaseFlow     | 22-mars-2023 17:21:14 | FFMESH_000007.msh | 28.3691    | 214.667    | 214.667   
 60    | FFDATA_000060.txt | BaseFlow     | 22-mars-2023 17:21:49 | FFMESH_000007.msh | 27.992     | 216.613    | 216.613   
 61    | FFDATA_000061.txt | BaseFlow     | 22-mars-2023 17:22:26 | FFMESH_000007.msh | 27.6289    | 218.562    | 218.562   
 62    | FFDATA_000062.txt | BaseFlow     | 22-mars-2023 17:23:02 | FFMESH_000007.msh | 27.2789    | 220.515    | 220.515   
 63    | FFDATA_000063.txt | BaseFlow     | 22-mars-2023 17:23:38 | FFMESH_000007.msh | 26.9412    | 222.469    | 222.469   
 64    | FFDATA_000064.txt | BaseFlow     | 22-mars-2023 17:24:12 | FFMESH_000007.msh | 26.6151    | 224.427    | 224.427   
 65    | FFDATA_000065.txt | BaseFlow     | 22-mars-2023 17:24:47 | FFMESH_000007.msh | 26.2999    | 226.387    | 226.387   
 66    | FFDATA_000066.txt | BaseFlow     | 22-mars-2023 17:25:21 | FFMESH_000007.msh | 25.9951    | 228.348    | 228.348   
 67    | FFDATA_000067.txt | BaseFlow     | 22-mars-2023 17:25:55 | FFMESH_000007.msh | 25.7       | 230.312    | 230.312   
 68    | FFDATA_000068.txt | BaseFlow     | 22-mars-2023 17:26:26 | FFMESH_000007.msh | 25.4143    | 232.278    | 232.278   
 69    | FFDATA_000069.txt | BaseFlow     | 22-mars-2023 17:27:05 | FFMESH_000007.msh | 25.1373    | 234.245    | 234.245   
 70    | FFDATA_000070.txt | BaseFlow     | 22-mars-2023 17:27:43 | FFMESH_000007.msh | 24.8688    | 236.214    | 236.214   
 
#################################################################################
 
.... CONTENT OF DIRECTORY ./WORK_ArcLength_Constant/MESHBF
     (couples of .txt/.ff2m files )
 
 Index | Name              | Type         | Date                 | Mesh file         | Re         | beta       | Energy     | U1         | U2         | bctype    
 1     | FFDATA_000001.txt | BaseFlow     | 22-mars-2023 16:43:55 | FFMESH_000001.msh | 1          | 3.8124     | 3.8124     | 0.75       | 1          | 0         
 
#################################################################################
 
.... CONTENT OF DIRECTORY ./WORK_ArcLength_Constant/MISC
     (couples of .txt/.ff2m files )
   NB this directory may contain various secondary files produced by StabFem,
      such as flowfields projected after adaptation but not recomputed, adaptation masks, etc... 
 
 Index | Name              | Type         | Date                 | Mesh file         | Re         | beta       | Energy     | U1         | U2         | bctype    
 1     | FFDATA_000001.txt | BaseFlow     | 22-mars-2023 16:44:05 | FFMESH_000002.msh | 10         | 18.5917    | 18.5917    | 0.75       | 1          | 0         
 2     | FFDATA_000002.txt | BaseFlow     | 22-mars-2023 16:44:22 | FFMESH_000003.msh | 30         | 106.998    | 106.998    | 0.75       | 1          | 0         
 3     | FFDATA_000003.txt | BaseFlow     | 22-mars-2023 16:44:43 | FFMESH_000004.msh | 50         | 154.689    | 154.689    | 0.75       | 1          | 0         
 4     | FFDATA_000004.txt | BaseFlow     | 22-mars-2023 16:45:04 | FFMESH_000005.msh | 55         | 164.412    | 164.412    | 0.75       | 1          | 0         
 5     | FFDATA_000005.txt | BaseFlow     | 22-mars-2023 16:45:29 | FFMESH_000006.msh | 60         | 171.999    | 171.999    | 0.75       | 1          | 0         
 6     | FFDATA_000006.txt | BaseFlow     | 22-mars-2023 16:45:56 | FFMESH_000007.msh | 65         | 178.162    | 178.162    | 0.75       | 1          | 0         
 
 
#################################################################################

redraw figure from database

figure; plot([sfs.BASEFLOWS.Re],[sfs.BASEFLOWS.beta]);xlabel('Re'); ylabel('\beta');xlim([ReMin,ReMax]);

figure; plot([sfs.BASEFLOWS.Re],[sfs.BASEFLOWS.Energy]);xlabel('Re'); ylabel('E');xlim([ReMin,ReMax]);

Plot last Base flow

figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8],'title',['Re = ',num2str(bf.Re),'; E = ',num2str(bf.Energy)] );
hold on;  SF_Plot(bf,'psi','contour','only','Clevels',[ - 1:.1:-.1, 0:.01:.0625,.1,.2, .5:.5:10],'xlim',[-1 12],'ylim',[0 8]);

% larger range
figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8],'title',['Re = ',num2str(bf.Re),'; E = ',num2str(bf.Energy)] );
hold on;  SF_Plot(bf,'psi','contour','only','Clevels',[ - 1:.1:-.1, 0:.01:.0625,.1,.2, .5:.5:10],'xlim',[-1 100],'ylim',[0 20]);
Note: To improve runtime build MEX function fftri2gridfast() from fftri2gridfast.c
Note: To improve runtime build MEX function fftri2gridfast() from fftri2gridfast.c

compare with base flow for Re=30 from main branch

bf= SF_Load('BASEFLOWS',6);
figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8],'title',['Re = ',num2str(bf.Re),'; E = ',num2str(bf.Energy)] );
hold on;  SF_Plot(bf,'psi','contour','only','Clevels',[ - 1:.1:-.1, 0:.01:.0625,.1,.2, .5:.5:10],'xlim',[-1 12],'ylim',[0 8]);

% larger range
figure; SF_Plot(bf,'ux','xlim',[-1 8],'ylim',[0 8],'title',['Re = ',num2str(bf.Re),'; E = ',num2str(bf.Energy)] );
hold on;  SF_Plot(bf,'psi','contour','only','Clevels',[ - 1:.1:-.1, 0:.01:.0625,.1,.2, .5:.5:10],'xlim',[-1 100],'ylim',[0 20]);


% [[PUBLISH]]
%
fclose(fopen('ArcLength_Constant.success','w+'));