Basic Building Blocks
Incompressible, inviscid, two-dimensional flow is now defined, and it was emphasized that many results of wide practical value and crucial importance are forthcoming from a theory that, at first glance, may seem to be so restricted by assumptions as to be of extremely limited value.
Before examining the defining differential equations and their solution, concepts regarding the kinematics of the flow are explained and defined. These concepts will prove useful as the theory is developed. In this section, several basic building blocks are established (some of which are independent of one another) and then set aside for later use. Patience is required in mastering these conceptual building blocks: The importance of the material can be appreciated only in retrospect after each building block plays its role in the analysis.