Unable to generate a proper contour plot

Greetings everyone,

I am trying to generate a contour plot of mach number. I have provided the code below as well as my output(PLOT.PNG). The output is not what I want. I want it to be completely filled with colours of mach number. I have attached the necessary files obtained from ANSYS FLUENT(ZIP file).

Any help is appreciated!

clc; clearvars; close all; % clear my workspace

% import the data

pname = '[insert directory here]';

fname = 'interior.dat'; % data from ANSYS FLUENT

prof_name = 'boundary_data.dat';

% reference variables

%ur = 127.54; % in m/s

%pr = 272609; % in Pa

Lr = 0.03989;%.3422e-3; % in m

% reading the file

a = importdata(strcat(pname,fname));

b = importdata(strcat(pname,prof_name));

% collecting variables

x = a.data(:,2); y = a.data(:,3); M = a.data(:,4);

% profile

xp = b.data(:,2) ; yp = b.data(:,3);

%%

% creating a matrix data or a structured data

xu = unique(round(x,4)); yu = unique(round(y,4)); % for better memory

[xm,ym] = meshgrid(xu,yu);

%% interpolate

Mm = griddata(x,y,M,xm,ym);

%um = griddata(x,y,u,xm,ym);

%vm = griddata(x,y,v,xm,ym);

%pm = griddata(x,y,p,xm,ym);

%% set undefined values outside the fluid domain

in = inpolygon(xm,ym,xp,yp);

xm(~in) = NaN; ym(~in) = NaN; Mm(~in) = NaN;

%% plot

%subplot(2,2,1)

%contourf(xm, ym, Mm, 'LineColor', 'none');

pcolor(xm,ym,Mm);shading interp; hold on;

plot(xp,yp,'.k'); hold off; axis equal;

clb = colorbar;

title(clb,'M');

xlabel('x/D');ylabel('y/D');

set(clb,'TickDir','out');

set(gca,'TickDir','out','layer' , 'top');

[Umeshraja]

Hello @Bamelari Jovani, it seems that the zip file is either corrupted or possibly empty, as I'm unable to extract it.

[Bamelari Jovani]

Dear @Umeshraja You can find the files here: https://drive.google.com/drive/folders/158I7MfqUD9yIXbiOkg7FYf0KYgu-OpXh?usp=sharing

Answer 1

[Umeshraja]

Hi @Bamelari Jovani

The lines highlighted below are indeed attempting to mask areas outside the fluid domain to prevent plotting data where it doesn't physically exist. However, this approach can sometimes cause problems, especially if the boundary isn't well-defined.

in = inpolygon(xm,ym,xp,yp);
xm(~in) = 0; ym(~in) = 0; Mm(~in) = 0;

Removing these lines result in contour plot completely filled with colours representing mach number as shown below.

Hope it helps!

[Bamelari Jovani]

Thank you @Umeshraja