Design Process and Flow Field Analysis of a Double Divergent Supersonic Nozzle: Enhancing Efficiency and Performance

Abstract

The dual bell nozzle concept's primary goal is to increase performance through the idea of selfadaptation for two operating regimes without mechanical activation. The dual bell nozzle type known as the planar double divergent nozzle (DDN) has a rectangular cross section. In this study we propose a numerical method for the design of the nozzle profile with double planar divergent. The design of the double divergent nozzle is carried out in two parts. The first divergent is a contour of a two-dimensional supersonic nozzle with a sharp-edged throat that gives uniform parallel flow at the exit. The method of characteristic applied to the two-dimensional isentropic flow of an ideal gas was used for the design of a supersonic planar nozzle. The contour of the second divergent (nozzle extension) is a polynomial. This is achieved using the direct method of characteristics. A numerical analysis of a double divergent nozzle, and a planar nozzle with the same area ratio and the same length using ANSYS-Fluent software. The analysis's findings indicated that the double divergent nozzle had a weight decrease of 0.61%. The thrust increase is estimated at 3.88% in the low-altitude operating mode for the double divergent nozzle.