Computational Analysis of Fluid Flow in a Rocket Nozzle

Abstract

“The thrust produced by a rocket motor is largely dependent upon the expansion of the product gases through a nozzle. The nozzle is used to accelerate the gases produced in the combustion chamber and convert the chemical-potential energy into kinetic energy so that the gases exit the nozzle at very high velocity. It converts the high pressure, high temperature and low velocity gas in the combustion chamber into high velocity gas of lower pressure and low temperature. ”The design of a nozzle has special importance in determining the thrust and performance of a rocket. In recent years, the design of the nozzle has received considerable attention as it directly impacts the overall performance of the rocket. This study aims to analyze the variation of flow parameters like pressure, temperature and velocity using finite volume method (FVM) solver with the standard k-ε turbulence model in computational fluid dynamics (CFD). The simulation of shockwave inside the divergent nozzle section through CFD is also investigated. In this regard, 06 nozzles have been designed using Design Modeler and CFD analysis of flow through the nozzles has been carried out using ANSYS Fluent. Three different cases were applied on all the design to investigate the performance. Based on the standard performance parameters available in the literature, one nozzle with the better performance was selected. The best design was further validated with already existing design in the literature by giving the same boundary conditions. This study’s design has shown better performance in all parameters compared to the design available in the literature.

Keywords: Converging-Diverging (C-D) Nozzle; CFD; Fluent; Shockwave; standard k-ε model