Purpose of winglets on airplanes?
Does anyone know the purpose of putting the winglets on airplanes? I know the obvious answer is that aeronautical engineers found that wings fly better with them there. But could someone tell me how that works? I'm curious in the concepts of aeronautical engineering without the detailed equations. What exactly do they do for the airflow over the wings? Does any one have any recommendations about a book or webpage to view on this?
Thanks for your help!