Analysis of Dual Bell Nozzle Configurations: Design Parameters and Performance Measurements

The auto-adaptation capability of the dual-bell nozzle (DBN) facilitates and enhances the performance of rocket propulsion systems, thus rendering it suitable for sea-level operations and efficient transitions at varying altitudes. This study compares the performances of three different types of DBNs in terms of thrust efficiency and altitude compensation. Additionally, a set of simulations is performed to investigate the key design parameters, such as the nozzle geometry, expansion ratio, and contour shapes, to evaluate their effect on the overall performance. After performing an extended literature review of dual-bell propulsion nozzles, the abovementioned parameters are examined systematically to provide deeper insights into their effects on thrust generation and altitude adaptability. The results show that thrust-optimised parabolic base nozzle designs can significantly enhance the thrust efficiency in aeroengines and facilitate adaptation to a wide range of altitudes. This study provides critical insights into the essential design aspects for optimising the performance of DBNs, thus contributing significantly to advancements in rocket propulsion. The obtained results offer valuable guidelines for enhancing nozzle design and accuracy, as well as facilitate efficiency improvement in aerospace applications, thereby ultimately improving the overall effectiveness of propulsion systems.