This list has carried a lot of discussion of "disk balloons" as a model for
how wings work. I have been repeatedly asked to review this model, so here
goes.
Executive summary:
* The disk-balloon model gets credit for correctly portraying several
features of the actual airflow.
* It even correctly portrays one rather non-obvious feature of the airflow.
* Alas it contains a significant element of arbitrariness.
* It does not correctly describe the interaction of the wing with the
ground, or with other nearby wings.
* It violates the known equations of motion.