Eventos Anais de eventos
COBEM 2023
27th International Congress of Mechanical Engineering
NUMERICAL INVESTIGATION FOR SUPERSONIC GAS SEPARATOR WITH CURVED NOZZLE
Submission Author:
Denis Fernando Gregório Júnior , SP , Brazil
Co-Authors:
Denis Fernando Gregório Júnior, Reinaldo Marcondes Orselli, Ricardo Galdino da SIlva, Bruno Souza
Presenter: Denis Fernando Gregório Júnior
doi://10.26678/ABCM.COBEM2023.COB2023-0879
Abstract
Supersonic gas separators are devices that allow the separation of heavier components of natural gas through supersonic flow expansion through a convergent-divergent nozzle. The temperature decreases along the divergent section until condensation of some components occurs with the formation of liquid droplets. The droplet separation is done by imposing centrifugation which conducts the condensed particles towards collectors attached to the nozzle wall. A key beneficial aspect of such supersonic separator devices is related to their compactness combined with the absence of moving parts, resulting in a small footprint and low maintenance cost. In this context, the purpose of this work is to investigate, through numerical simulations, the flow behavior of a supersonic convergent-divergent nozzle, as used in the supersonic gas separator device, but with a nozzle of curved shape to generate centrifugal force. The Finite Volume Method is used for the numerical simulations. Due to the high turbulence in the flow, the flow is resolved based on RANS (Reynolds Averaged Navier-Stokes) equations, particularly, with the k-ε RNG and k-ω SST turbulence models. Subsequently, the curvature of the initial geometry is modified in order to generate higher centrifugal force; parameters such as the radius of curvature and the length of the supersonic section are reduced. Flow features along the nozzle length such as pressure distribution, temperature, centrifugal force level as well as shock wave topology and position are shown and analyzed. With the different curvature shapes tested, the centrifugal g force attained levels ranging from 118000g up to 214000g. Particularly, in comparison with a straight nozzle, due to the curvature shape, a sequence of several slight oblique shock waves was noticed in the supersonic expansion region. A possible explanation for this sequence of oblique shock waves is that along the curved supersonic expansion, the flow path of the inner nozzle arch side is shorter with respect to the outer arch side that has a longer path.
Keywords
Computational fluid dynamics (CFD), Turbulence Models, fluid mechanics, Shock Waves, Supersonic separators
