 note interact boundari layer inviscid flow note interact boundari layer inviscid flow classic boundari-layer theori flow bodi reynold number aeronaut interest consid compos regim inviscid flow thin boundari-layer region adjac bodi point view lead approxim curv surfac layer neglig small addit assumpt inviscid flow irrot lead requir outer edg boundari layer theori interact regim account simpl correct bodi shape base boundari-layer displac thick connect hyperson laminar boundari layer classic point view modifi interact flow regim lead self-induc axial pressur gradient consid purpos note point type interact practic fundament interest mach number consid hyperson boundari-layer theori consid theori 