In this text we will cover the range between these two extremes: When Viscosity and Momentum are Both Important, at Least in Some Significant Part of the Flow Field. Foreword, Navier - Stokes Equation, Vorticity - Stream Function Method, Finite Difference Method, Finite Volume Method, Finite Element Method, Turbulence, Three Dimensional Flow, Tecplot vs. TP2, Compilers, Finite Differences, Arrays, Green's Lemma, Elements, Exact Solutions, Transient Solutions.