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 asthe planar double divergent nozzle (DDN) has a rectangular cross section. In this study we propose anumerical method for the design of the nozzle profile with double planar divergent. The design of the doubledivergent nozzle is carried out in two parts. The first divergent is a contour of a two-dimensional supersonicnozzle with a sharp-edged throat that gives uniform parallel flow at the exit. The method of characteristicapplied to the two-dimensional isentropic flow of an ideal gas was used for the design of a supersonic planarnozzle. The contour of the second divergent (nozzle extension) is a polynomial. This is achieved using thedirect method of characteristics. A numerical analysis of a double divergent nozzle, and a planar nozzlewith the same area ratio and the same length using ANSYS-Fluent software. The analysis's findingsindicated that the double divergent nozzle had a weight decrease of 0.61%. The thrust increase is estimatedat 3.88% in the low-altitude operating mode for the double divergent nozzle.