having problems with implementing the wake rollup for a panel method
 

Hello,

First I am a beginner to panel methods so I might be making some simple mistakes. I am currently developing an unsteady panel method (in 2D) after having had some success with steady panel methods. My approach is to have bodies represented by doublets/sources and have the wake represented by doublets.

In Katz and Plotkin's book, an algorithm is shown for the unsteady panel method in which there is a wake rollup routine. It says that this is used to calculate the local induced velocities for all the wake panel corner points. The panels are then moved accordingly. The calculation of the induced velocity at a wake panel corner point sum the effects of all the singularity elements, both on the body and in the wake. I am confused because if I calculate the contribution of wake panels on either side of a wake corner, then I get a singularity. How do I avoid this?

Many thanks,

Alex