CFD Online Discussion Forums - Can anybody explain the implementation of ADI?

Hi friends,

I'm trying to use ADI method in my code (the code uses SIMPLE method by two steps of explicit and implicit) but I do understand it.
Why do I need to apply ADI? because my code is slow and found out that the bottleneck of my code is explicit calculation.

What is explicit section:
This section easily calculates velocities except pressure which would calculated at implicit part and update velocities. The main loops for explicit section is:

http://soliton.ae.gatech.edu/labs/wi...6/Image490.gif

Code:

For (i=0, i<nx , i++)

{

For (j=0, j<ny , j++)

{

Ubar=  ...  // calculation of velocities without pressure

Vbar=  ...  // calculation of velocities without pressure

}

}

How can I use other algorithm to improve my code calculation speed ?
Any suggestions ?