Numerical Strategy for Unsteady Two-Way Coupled Polydisperse Sprays: Application to Solid-Rocket Instabilities

The accurate simulation of polydisperse sprays strongly coupled to unsteady gaseous flows is a major issue (e.g., for solid rocket motor optimization). The Eulerian multifluid method has proven to account for polydispersity efficiently by describing continuously droplet sizes that are sorted into “f...

Full description

Saved in:
Bibliographic Details
Published in:Journal of propulsion and power 2014-05, Vol.30 (3), p.727-748
Main Authors: Doisneau, F, Sibra, A, Dupays, J, Murrone, A, Laurent, F, Massot, M
Format: Article
Language:English
Subjects:
Accuracy
Acoustics
Computational fluid dynamics
Coupling
Droplets
Gas flow
Joining
Mathematical models
Numerical methods
Optimization
Polydispersity
Propulsion
Rockets
Solid propellant rocket engines
Solid rocket motors
Sprayers
Sprays
Supersonic nozzles
Unsteady
Unsteady flow
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The accurate simulation of polydisperse sprays strongly coupled to unsteady gaseous flows is a major issue (e.g., for solid rocket motor optimization). The Eulerian multifluid method has proven to account for polydispersity efficiently by describing continuously droplet sizes that are sorted into “fluids,” which are coupled to the gas through drag and heat source terms. The potential of this model to capture polydisperse two-way interactions has not been addressed. Such an interaction is described through two strongly coupled systems of equations, which involve a large spectrum of scales in both time and space and require specific numerical methods to reach accuracy and predictability with an acceptable computational cost. In this paper, we define the physics and key issues of polydisperse spray acoustics, identify physically relevant test cases, and investigate the abilities of multifluid systems. We also describe the numerical peculiarities related to strong coupling, at high mass loading, of polydisperse sprays in unsteady gaseous flowfields. The case of small droplets (i.e., with relaxation timescales that are shorter than the gas flow scales) is carefully studied. We finally introduce, thoroughly study, and adapt to an industrial-oriented code a new numerical strategy with a high level of flexibility, which can be adapted to accuracy needs. The method is tested on an unsteady, polydisperse solid rocket motor to prove its feasibility and efficiency for two-way coupling in a supersonic nozzle, which is representative of the difficulties encountered in a wide range of unsteady flows.
ISSN:0748-4658
1533-3876
DOI:10.2514/1.B34862