Experimental and Analytical Design Verification of the Dual-Bell Concept

Abstract

The dual-bell nozzle concept has been investigated by means of analytical and experimental work. Based on earlier analytical and numerical work published by the authors, different dual-bell nozzles were designed and experimentally tested, in order to explore this concept regarding its aerodynamic characteristics. This experimental work included cold gas subscale tests and hot gas subscale tests, which were performed within a joint German/Russian Research Programme TEHORA, and complementary in the German National Technology Programme TEKAN. It is shown that depending on the type of nozzle contour used for the dual-bell nozzle extension, a sudden transition from sea-level to altitude mode operation can be achieved. Furthermore, important information from the hot gas tests regarding the wall heat transfer were gained.