 theori core lead edg vortex theori core lead edg vortex flow slender delta wing incid observ roughli axial symmetr core spiral fluid form roll shear layer separ lead edg aim report predict flow field vortex core appropri condit edg basic assumpt core addit assum flow axial symmetr incompress admit outer inner solut core equat motion outer solut sub-core ignor flow inviscid rotat conic solut consist simpl express veloc compon pressur inner solut appli diffus sub-core flow laminar approxim base boundari condit analog boundari layer theori solut case approxim present tabular form sampl calcul yield good qualit fair quantit agreement experiment measur 