 investig separ flow ii flow caviti heat transfer investig separ flow ii flow caviti heat transfer portion paper describ studi intern structur separ flow notch free-stream mach number 3 observ includ flow visual spark- schlieren pictur fluctuat free shear layer studi diffus heat sourc separ region second describ measur local heat transfer wall extern mach number length-to-depth ratio caviti ratio oncom boundari layer thick notch depth turbul flow region thermal to-momentum thick ratio boundari layer final geometri intern boundari separ region vari systemat basi observ simpl model flow heat transfer separ region formul 