Finite Difference - Nonuniform mesh

Excom · April 28, 2009, 08:56

Hi

I am trying to solve Poissons equation with the use of the finite difference method.

Is there any one that can tell me how the second order derivative lookes like in the interface between a fine and a rough mesh?

I know that this has nothing to do with fluid dynamics, but maybe some one is familiar the finite difference method and is able to help me.

Thanks in advance

harishg · April 28, 2009, 10:21

You can get the finite difference formula for non uniform mesh by writing the derivative as
f_primeprime = a f_i-1+ b f_i + c f_i-1
Expand the RHS using Taylor's series and match the coefficients on both sides to get a,b anc c.

CFDstudent · May 11, 2009, 19:08

did this answer your question?

April 28, 2009, 08:56	Finite Difference - Nonuniform mesh	#1
Excom New Member Join Date: Apr 2009 Posts: 1 Rep Power: 0	Hi I am trying to solve Poissons equation with the use of the finite difference method. Is there any one that can tell me how the second order derivative lookes like in the interface between a fine and a rough mesh? I know that this has nothing to do with fluid dynamics, but maybe some one is familiar the finite difference method and is able to help me. Thanks in advance

May 11, 2009, 19:08	finite difference approximation to 2nd derivative	#3
CFDstudent New Member Join Date: Apr 2009 Posts: 6 Rep Power: 17	did this answer your question?

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April 28, 2009, 10:21		#2
harishg Senior Member N/A Join Date: Mar 2009 Posts: 189 Rep Power: 17	You can get the finite difference formula for non uniform mesh by writing the derivative as f_primeprime = a f_i-1+ b f_i + c f_i-1 Expand the RHS using Taylor's series and match the coefficients on both sides to get a,b anc c.