Numerical Study of Microscale Monopropellant Fuel Injection Using Two-Phase Slug Formation

Gas and liquid converging at a microchannel cross junction results in the formation of periodic, dispersed microslugs. This microslug-formation phenomenon has been proposed as the basis for a fuel-injection system in a novel, discrete monopropellant microthruster design for use in next-generation miniaturized satellites. Experimental work by McCabe et al. (“A Micro-Scale Monopropellant Fuel Injection Scheme Using Two-Phase Slug Formation,” Journal of Propulsion and Power, Vol. 27, No. 6, 2012, pp. 1295–1302) demonstrated the ability to generate fuel slugs with characteristics commensurate with the intended application. In this work, numerical modeling and simulation is used to further study this problem and identify the sensitivity of the slug characteristics to key material properties including surface tension, contact angle, and fuel viscosity. These concerns are of practical concern for this application due to the potential for thermal variations and/or fluid contamination during typical operation. For...