The structure of aerodynamic heating in three-dimensional shock wave/turbulent boundary layer interactions induced by sharp and blunt fins

Abstract

I . INTRODUCTION T h e det ai I ed structure of aerodynamic heating in three-dimensional r h ~ c k waveiturbulent boundary layer iniuced by sharp and blunt fins are reyealed by a n e a methud developed by the present authors. T h e new method is based a n a n e w type o f thin-film heat transfer gabge with high spatial resolution and fast response. I t c a n be used not only for shock tunnels but a l s o for wind tui.neis with long f l o w duration. T h e rentarkable features o f the structure of aerodynamic heating in three-dimensional shock wavelturbulent boundary layer interaction region a r e obtained. T h e r e s u l t s provide valuable information for the understanding of the threedinensional shock induced aerodynamic heating phenomena. %-, Experiments are performed under the tezting conditions of Mach number o f 4 , total pressure of 1 . 2 MPa. wall temperature condition TwITo of 0 . 6 5 and Reynolds number o f 1 . 2 ~ 1 0 ~ . F o r Sharp fin interaction the measurements a r e conducted f o r 4 . I O and 1 6 degrees o f wedge angle o f f i n in order to investigate the f l o w f i e l d s from at incipient separation condition to a t fully separated cordition with secondary separation. for blunt f i n interaction two fins with leading edge diameters of 6 and 1 0 mm are used to observe the influence of the leading edge diameter of the fin on the p r e s s u r e and heat-transfer distributions. T h e heat transfer rate changes drastically in the interaction region with pressure. A l s o the strong relation of peak heating a n d f l o w reattachment a r e observed. One of the s e v e r e problems in high speed flight is the intensive aerodynamic heating in the interaction region of shock w a v e s and turbulent boundary l a ) e r s , Many experimental investigations abcut aerodynamic heating caused by the shock wave-turbulent boundary layer interact ions have been c o n d u ~ t e d ~ ' ~ ' ~ ~ ) . For practical design consideration the most Important phenomenon is the appearance of peak heat transfer in the interaction regions. T h e peak heat transfer occurs with a small length scale in the interaction. T h e detailed features and its association with the 5trueture o f the flow fields have not been revealed sufficlentlv. Recently there w e r e many experimental measurements of threedin:enrionaI shock waveiturbulent boundary layer interaction reported. O s k a m and Vas'), Kubota a n d Stollery6). Dolling and Boedonoff7), Settles and Lu8). Settles and Klmmelg). Murakami and Aihara). and the present authors investigated the flow fields of the three-dimensional shock wave/turbulent boundary layer interaction induced by sharp fins and blunt fins. However those experimental efforts were mainly limited to f l o w visualization by oil f l o w technique and measurement o f pressure distributions. I t is important to know the detailed distribution o f s u r f a c e heat flux in order to reveal the s t r u c t u ~ e o f aerodynamic heating and to provide information for numerical simulation o f heat flux calculations. we have developed a new type of heat f l u x sensor t h a t h a s high .spatial resolution and fast response and can be Associate 'Professor, Aeronautical 'used in wind tunnels with long f l o w Engineering. Member o f AlAA I. Professor. Faculty of Engineering. duration. Also the theory o f measurement. the method of manufacturing. Member o f AIAA *.* Graduate Student. Aeronautical and the calibration method f o r the new Engineering sensor have been e s t a b l i ~ h e d l ~ ) . T h e Copyright @ 1989 by S.Aso,M.Hayashi and A.'lan. Published by the American Institute of Aeronautics and Astronautics, Inc. with permission. .-/