Hydrodynamic Instabilities Modeling in Hybrid Rocket Engines

Abstract

Table des matières Liste des figures xii Liste des tableaux xiii Nomenclature xv A Récapitulatif du modèle d'instabilités hydrodynamiques Bibliographie viii Modélisation des instabilités hydrodynamiques dans les moteurs-fusées hybrides xviii Modélisation des instabilités hydrodynamiques dans les moteurs-fusées hybrides 1. Une partie de ce chapitre a fait l'objet d'un article dans le Journal of Propulsion and Power : « Vortex shedding influence on hybrid rocket pressure oscillations and combustion efficiency » [62]. Modélisation des instabilités hydrodynamiques dans les moteurs-fusées hybrides

Bridging the Technology Gap: Strategies for Hybrid Rocket Engines

“…Finally, it can be argued whether Reynolds-averaged Navier-Stokes approaches (as in the majority of HRE simulations) are ideally suited for the complex wall blowing and pyrolysing phenomena at the fuel surface. Nevertheless, numerical simulations of HREs are improving significantly, be it in the modelling of hydrodynamic instabilities [149,150], swirl injection [138,[152][153][154], shape changing simulations [153][154][155][156][157] (see Figures 7 and 8), complex geometries such as helices [158][159][160], rotated grains [144,161], throttling [72,162], or nozzle erosion [94,163]. Simplified geometries and simulations carried out on the average fuel port diameter are considerably less computationally costly compared to multiple instances of the fuel port progression, with both providing satisfactory representations of the HRE flow field and local regression rates [157,164].…”

Effect of Protrusion on Combustion Stability of Hybrid Rocket Motor

“…In addition to these, the instabilities related to the oxidizer feed system coupled with chamber pressure oscillations, atomization and vaporization of liquid oxidizers, and bulk mode instabilities have been observed in hybrid rockets [27]. Hydrodynamic instabilities in the hybrid rocket are linked with the unstable flow field inside the combustion chamber [33]. The unstable flow field is a result of the sudden changes in the combustion chamber geometry that could modify flow behavior; this could result in combustion instabilities.…”

“…Hydrodynamic instabilities in the hybrid rocket are linked with the unstable flow field inside the combustion chamber [33]. The unstable flow field is a result of the sudden changes in the combustion chamber geometry that could modify flow behavior; this could result in combustion instabilities.…”

“…However, the combustion instabilities in hybrid rockets have to be dampened because; they can create mechanical vibrations that cause damage to the control systems, payloads, and other structural parts of the launch vehicle. Several researchers have tried to understand the combustion instabilities in hybrid rockets under a wide range of operating conditions and fuel-oxidizer combinations [27][28][29][30][31][32][33]. Based on these studies, the classification of combustion instabilities and their driving mechanism in hybrid rockets are summarized in Table 2.…”