CFD Online Logo CFD Online URL
Home > Forums > Main CFD Forum

unsteady flow - matlab - for loop questions

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   September 5, 2011, 19:03
Default unsteady flow - matlab - for loop questions
Senior Member
Join Date: Jun 2010
Posts: 111
Rep Power: 9
Hooman is on a distinguished road
Hi all,
I am writing a code for an unsteady flow in maltab. This code is over simplified just to realize where I am going wrong and understand the basic first...

n = number of time steps
h = number of cells
v1 = zeros(h,n+1); %v1(x,t)
v1(1,= 0; %boundary condition

for j = 1: n+1
for j = 1: h
v1(i,j+1) = v1(i,j) + dt*eye(h,h)*2*v(i,j); %Euler time stepping
v1(end,j+1)=1; %boundary condition

Obviously this code does not work. But hopefully it will help in understanding my questions:
1) v1 is mean to be a (h,1) matrix at each time step. but when I apply
eye(h,h)*2*v(i,j), the code tries to multiply a (h,h) matrix with a (h,j) matrix, and not a (h,1) matrix. so I get errors. I am not sure how to change that so that eye(h,h) is multiplied by that v of each time...
2) In general, is this a reasonable approach to solve an unsteady flow problem.

Thank you in advance!
Hooman is offline   Reply With Quote


Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Airfoil conditions for unsteady flow Dave Main CFD Forum 3 April 24, 2008 17:11
Unsteady simulation of flow past wheel Tom FLUENT 8 January 18, 2006 11:54
Unsteady flow in FLUENT Vidya Raja FLUENT 2 November 2, 2005 17:29
Unsteady Flow in FLUENT Vidya Raja FLUENT 0 November 1, 2005 18:54
Initial Conditions in unsteady turbulent flow Z. Zeng Main CFD Forum 5 April 28, 1999 17:38

All times are GMT -4. The time now is 16:05.