Analysis of hydrodynamic (landau) instability in liquid-propellant combustion at normal and reduced gravity

Conference · Wed Oct 01 04:00:00 EDT 1997

DOI:https://doi.org/10.2172/563184· OSTI ID:554740

Margolis, S B

The burning of liquid propellants is a fundamental combustion problem that is applicable to various types of propulsion and energetic systems. The deflagration process is often rather complex, with vaporization and pyrolysis occurring at the liquid/gas interface and distributed combustion occurring either in the gas phase or in a spray. Nonetheless, there are realistic limiting cases in which combustion may be approximated by an overall reaction at the liquid/gas interface. In one such limit, distributed combustion occurs in an intrusive regime, the reaction zone lying closer to the liquid/gas interface than the length scale of any disturbance of interest. Such limiting models have recently been formulated thereby significantly generalizing earlier classical models that were originally introduced to study the hydrodynamic stability of a reactive liquid/gas interface. In all of these investigations, gravity appears explicitly and plays a significant role, along with surface tension, viscosity, and, in the more recent models, certain reaction-rate parameters associated with the pressure and temperature sensitivities of the reaction itself. In particular, these parameters determine the stability of the deflagration with respect to not only classical hydrodynamic disturbances, but also with respect to reactive/diffusive influences as well. These instabilities thus lead to a number of interesting phenomena, such as the sloshing type of waves that have been observed in mixtures of HAN and triethanolammonium nitrate (TEAN) with water. Although the Froude number was treated as an O(l) quantity in these studies, the limit of small inverse Froude number corresponding to the microgravity regime is increasingly of interest. In the present work, the author formally exploits this limiting parameter regime to compare some of the features of hydrodynamic instability of liquid-propellant combustion at reduced gravity with the same phenomenon at normal gravity.

• Research Organization: Sandia Labs., Livermore, CA (United States)
• Sponsoring Organization: USDOE Assistant Secretary for Energy Efficiency and Renewable Energy, Washington, DC (United States); National Aeronautics and Space Administration, Washington, DC (United States)
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 554740
• Report Number(s): SAND--97-8542C; CONF-9705199--; ON: DE97054479; CNN: Contract C-32031-E
• Country of Publication: United States
• Language: English

Related Subjects

40 CHEMISTRY
COMBUSTION
EXPLOSIVES
HYDRODYNAMICS
INSTABILITY
LIQUID FUELS
ROCKETS