How do I plot Streamlines of velocity components of spherical coordinate system?

13 次查看（过去 30 天）

显示更早的评论

Jagadeesh Korukonda 2022-12-13

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1877222-how-do-i-plot-streamlines-of-velocity-components-of-spherical-coordinate-system

评论： Jagadeesh Korukonda 2022-12-15

采纳的回答： VBBV

在 MATLAB Online 中打开

I solved Navier stokes in Spherical coordinates and I got velocity field inside a sphere i.e

If I plot contours using the code below its working. But, The same technique is not working for streamlines, instead I'm getting blank.

The streamlines are look like this

nr = 21;

nth = 21;

L = 1;

r = linspace(0,1,nr);

th = linspace(0,pi,nth);

[R,Th] = meshgrid(r,th);

Xi = R.*cos(Th); Yi = R.*sin(Th);

ui = (R.^2-1)/2/(L+1).*cos(Th);

vi = (1-2*R.^2)/2/(L+1).*sin(Th);

figure;contourf(Xi,Yi,ui,100,'LineStyle','none');axis image

figure;contourf(Xi,Yi,vi,100,'LineStyle','none');axis image

figure;streamline(Xi,Yi,ui,vi)

I'm getting streamlines as empty, can anyone help me in this regard?

Thanks in advance.

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

请先登录，再回答此问题。

采纳的回答

VBBV 2022-12-13

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/1877222-how-do-i-plot-streamlines-of-velocity-components-of-spherical-coordinate-system#answer_1126967

在 MATLAB Online 中打开

verts = stream2(Xi,Yi,ui,vi,R,Th);
streamline(verts);

5 个评论
显示 3更早的评论隐藏 3更早的评论

VBBV 2022-12-15

在 MATLAB Online 中打开

Ok, it seems your equations are in spherical coordinates, so use sph2cart function

clc

clear all

close all

nr = 21;

nth = 21;

L = 1;

r =linspace(-1,1,nr);

th =linspace(0,pi,nth);

[R,Th] = meshgrid(r,th);

[x y z] = sph2cart(cos(Th),sin(Th),R);

Xi = (R).*cos(Th);

Yi = R.*sin(Th);

ui = ((R.^2-1)/(2*(L+1))).*cos(Th);

vi = ((1-2*R.^2)/(2*(L+1))).*sin(Th);

% figure;contourf(Xi,Yi,ui,100,'LineStyle','none');axis image

% figure;contourf(Xi,Yi,vi,100,'LineStyle','none');axis image

streamslice(x,y,ui,vi);

Jagadeesh Korukonda 2022-12-15

在 MATLAB Online 中打开

Thank you @VBBV

I've made small modification to your code. now its working fine. since my r-domian is [0 1] only.

clc

clear all

close all

nr = 5;

nth = 5;

L = 1;

r =linspace(0,1,nr);

th =linspace(0,pi,nth);

[R,Th] = meshgrid(r,th);

[x y z] = sph2cart(cos(Th),sin(Th),R);

Xi = (R).*cos(Th);

Yi = R.*sin(Th);

ui = ((R.^2-1)/(2*(L+1))).*cos(Th);

vi = ((1-2*R.^2)/(2*(L+1))).*sin(Th);

UI = [fliplr(ui(:,2:end)) ui];

VI = [fliplr(vi(:,2:end)) vi];

X1 = [fliplr(-x(:,2:end)) x];

Y1 = [fliplr(-y(:,2:end)) y];

streamslice(X1,Y1,UI,VI); axis image

请先登录，再进行评论。

类别

Image Processing and Computer Vision Computer Vision Toolbox Recognition, Object Detection, and Semantic Segmentation Image Category Classification

在 Help Center 和 File Exchange 中查找有关 Image Category Classification 的更多信息

产品

MATLAB

版本

R2022b

Community Treasure Hunt

Find the treasures in MATLAB Central and discover how the community can help you!

Start Hunting!

Translated by