* constant strength - simple, large number of panels required
* linear varying strength - reasonable answer, little difficulty in creating well-posed problems
* quadratic varying strength - accurate, more difficult to create a well-posed problem
Some techniques are commonly used to model surfaces.
* Body Thickness by line sources
* Body Lift by line doublets
* Wing Thickness by constant source panels
* Wing Lift by constant pressure panels
* Wing-Body Interface by constant pressure panels