Error: Unable to perform assignment because the left and right sides have a different number of elements.

I am attempting to develop transfer function class for the dual porosity model. I have written the scripts and vetted to ascertain correct syntax and formulation. In my dual porosity model - (code #1 below), I have to define a transfer function class already developed. But when I run the model, I keep getting this error: Unable to perform assignment because the left and right sides have a different number of elements - with details in code #2 below

I will really appreciate any advice and tips to rectify this bug.

Thanks,

Emeka.

Code #1 - Dual Porosity Model

%% Two-phase water injection in an oil-saturated dual-porosity reservoir. 
% Water flows quickly in the fracture system, while transfer to the matrix
% happens via spontaneous imbibition.
clear;
clc;
close all;

mrstModule add ad-blackoil ad-core ad-props dual-porosity

%% Set up grid
G = cartGrid([60, 1, 1], [60, 1, 1]*meter);
G = computeGeometry(G);

%% Set up rock properties
rock_matrix = makeRock(G, 10*milli*darcy, .1);
rock_fracture = makeRock(G, 100*milli*darcy, .01);

%% Set up fluid
fluid_matrix = initSimpleADIFluid('phases', 'WO', ...
                               'rho',     [1000, 800]*kilogram/meter^3,...
                                'c',       [1e-20, 1e-20]/barsa);
fluid_fracture = initSimpleADIFluid('phases', 'WO', ...
                               'rho',     [1000, 800]*kilogram/meter^3,...
                                'c',       [1e-20, 1e-20]/barsa);


Pe  = 0.15*psia;
fluid_matrix.pcOWm = @(swm)Pe.*swm.^0.5;
fluid_matrix.krWm = @(swm)swm.^2;                           
fluid_matrix.krOm = @(swm) (1-swm).^2; 
fluid_matrix.krWm_h = @(swm_av)swm_av.^2;                           
fluid_matrix.krOm_h = @(swm_av) (1-swm_av).^2;

%% Set the DP model. Here, a two-phase model is used. Rock and fluid
% are sent in the constructor as a cell array {fracture,matrix}
model = TwoPhaseOilWaterModelDP(G, {rock_fracture,rock_matrix},...
                                   {fluid_fracture,fluid_matrix});
                                   
%% Initializing state  
eps = 0.01;
state = initResSol(G, 2.5*psia, [eps, (1-eps)]);
state.wellSol = initWellSolAD([], model, state);
state.pressure_matrix = state.pressure;
state.sm = state.s;


%% Setting transfer function. This step is important to ensure that fluids
% will be transferred from fracture to matrix (and vice-versa). The second argument is the matrix block size. Another
% possible transfer function to be used in this model would be:
model.transfer_model_object = G_TF2_QC('G_SF',[5,5,5]);

%% Boundary conditions
bc = pside([], G, 'xmin', 500*psia, 'sat', [1,0]);
bc = pside(bc, G, 'xmax', 2.5*psia, 'sat', [0,1]);

%% Solver
solver = NonLinearSolver();

%% Validating model
model = model.validateModel();

%% Figure
fig1 = figure('Position',[100,100,1200,600]);
fig1.Color = 'w';
colormap('jet');

%% Time loop
dt = 1*day;
tmax = 1000*day;
t = 0;
while t<=tmax
    
    disp(['Time = ',num2str(t/day), ' days'])
    state = solver.solveTimestep(state, dt, model, 'bc', bc);
    
    figure(fig1)
    subplot(2,2,1);
    p = plotCellData(G,state.s(:,1));
    p.EdgeAlpha = 0;
    colorbar;
%    caxis([0,1]);
    set(gca,'FontSize',16);
    xlabel('x')
    ylabel('y')
    
    subplot(2,2,3);
    p = plotCellData(G,state.sm(:,1));
    p.EdgeAlpha = 0;
    colorbar;
    caxis([0,1]);
    set(gca,'FontSize',16);
    xlabel('x')
    ylabel('y')
    
    figure(fig1)
    subplot(2,2,2);
    plot(G.cells.centroids(:,1),state.s(:,1),'LineWidth',1.5,'Color','r');
    set(gca,'FontSize',16);
    xlabel('x')
    ylim([0,1])
    ylabel('Swf [-]')
    
    subplot(2,2,4);
    plot(G.cells.centroids(:,1),state.sm(:,1),'LineWidth',1.5);
    set(gca,'FontSize',16);
    xlabel('x')
    ylim([0,1])
    ylabel('Swm [-]')

    drawnow;
    
    t = t+dt;
    
end

Code #2 - Error messgage

Time = 0 days
264         end
Unable to perform assignment because the left and right sides have a different number of elements.

Error in getConvergenceValuesCNV (line 101)
            CNV(ph) = B_avg*dt*mv;

Error in DualPorosityReservoirModel/getConvergenceValues (line 388)
            [v_cnv, names_cnv, tol_cnv, is_cnv] = getConvergenceValuesCNV(model, problem);

Error in PhysicalModel/checkConvergence (line 604)
        [values, tolerances, names] = getConvergenceValues(model, problem, varargin{:});

Error in PhysicalModel/stepFunction (line 676)
        [convergence, values, resnames] = model.checkConvergence(problem);

Error in NonLinearSolver/solveMinistep (line 352)
                    model.stepFunction(state, state0, dt, drivingForces, ...

Error in NonLinearSolver/solveTimestep (line 203)
                    solveMinistep(solver, model, state, state0_inner, dt, drivingForces);

Error in example_2ph_drainage (line 68)
    state = solver.solveTimestep(state, dt, model, 'bc', bc);

Answer 1

[David Hill]

Put a stop in on this line of code:

CNV(ph) = B_avg*dt*mv;

Then inspect each variable size (ph, B_avg, ... ). You can also perform the calculation (B_avg*dt*mv) in the command window. The sizes are different on the left vs. right side.

Answer 2

[Chukwuemeka Enemanna]

Thank you David, I think I rectified that bug. I skipped the 'dot' notation in calculating one of my variables so I had a 60x60 matrix rather than a 60x1 matrix in discomformity with the rest of the variables. Thanks for your feedback, much appreiated.

Emeka.