Panel methods employing surface distributions of source and vortex singularities based on the solution of boundary integral equations have been extensively used for modeling external and internal aerodynamic flows. Part 1 describes the surface vorticity method and illustrates applications of this technique over a wide range of engineering problems in aerodynamics and turbomachines, including lifting aerofoils and cascades, mixed-flow and rotating cascades for fans, pumps or turbines, meridional flows in turbomachines, flow past axisymmetric bodies, ducts and ducted propellers or fans. Part 2 extends surface vorticity modeling to the fairly new CFM field of vortex dynamics or vortex cloud theory. Methods are developed, again from first principles, to deal with shear layers, boundary layers, periodic wakes, bluff-body flows, cascades and aerofoils including the use of stall control spoilers. A number of useful computer programs are included.