NACA Research Memorandums

This paper presents the results of an investigation of sting-support\ud interference on afterbody drag at transonic speeds. Stings with varying\ud diameter, cone angle, and cylindrical length were tested at the rear of a\ud model with various afterbody shapes. The data were obtained at an angle\ud of attack of O deg. and at Mach numbers from 0.80 to 1.10. It was found that,\ud in general, the addition of a sting caused a drag reduction. A method is\ud presented whereby approximate sting-interference corrections may be made\ud to models with afterbodies and sting supports of similar size and scale to\ud those of this paper provided the boundary layer is turbulent at the model\ud base and the Reynolds numbers are of the same order of magnitude.\ud Reynolds number of the tests presented varied from 15.0 x 10 (exp 6) to 17.4 x 10 (exp 6)\ud based on body length.\ud Sting effects from this investigation are compared with data of jet\ud effects on the same afterbodies. The results of this comparison indicate\ud that for the more gradually contoured afterbodies, a sting shape can be\ud found which will duplicate the jet effects, but that for blunt afterbodies\ud no solid sting shape will duplicate the jet effects