A systematic experimental study was performed to elucidate the conditions for which cellular patterns of diluted hydrogen diffusion flames near extinction were observed. The formation of cellular instabilities was studied for several burners: jet burners (axisymmetric jet and two-dimensional jet) and a novel one-dimensional burner. The fuel and oxidizer Lewis numbers and the initial mixture str...

Single-chamber fuel cells (SCFC) are ones in which the fuel and oxidizer are premixed, and selective electrode catalysts are used to generate the oxygen partial pressure gradient that in a conventional dual-chamber design is produced by physical separation of the fuel and oxidizer streams. SCFCs have been shown capable of generating power densities above 700 mW/cm with appropriate catalysts, ma...

A series of static hybrid rocket firings were done in a laboratory scale motor using paraffin wax fuel with gaseous oxygen and nitrous oxide oxidizers. A five element swirl injector was used to inject the oxidizer at the head end of the motor. A pyrotechnic igniter was used to initiate the combustion. The combustion of fuel grain was carried out for a fixed duration and at different oxidizer in...

The development of a shock-induced detonation driver for enhancing the performance of a shock tube is described. The detonation wave is induced by the expansion of helium or air. Various gaseous fuel–oxidizer combinations are examined. This method produces a detonation wave which propagates downstream that transitions into a shock wave in the driven section. High-enthalpy flows with a maximum t...

steep temperature gradient is established in the solid This gradient extends to a depth of several microns, depending upon the external heat-flux rate As the propellant surface layers approach 150°C, the intermosaic blocks of the oxidizer particles decompose, and gaseous products diffuse to the oxidizer particle-fuel interface From ammonium perchlorate decomposition studies, the over-all reacti...

Fuel droplets in combustors interact strongly with flames and turbulence in practical liquid-fueled combustors of terrestrial and aerial propulsion systems (Williams 1965; Sirignano 1999). Although a great deal of physical understanding has been achieved in purely gaseous combustion over the last century, not much is currently known about spray combustion at the fundamental level. In this short...

Enhancement of Volumetric Specific Impulse in HTPB/Ammonium Nitrate Mixed Hybrid Rocket Systems by Jacob W. Forsyth, Master of Science Utah State University, 2016 Major Professor: Dr. Stephen A. Whitmore Department: Mechanical and Aerospace Engineering Hybrid rocket systems are safer and have higher specific impulse than solid rockets. However, due to large oxidizer tanks and low regression rat...

The present study experimentally investigates fundamental characteristics of diffusion flames and the importance of gas radiation. In particular, transient measurements of flame growth, temperature, and radiation intensity of an expanding spherical diffusion flame in microgravity are used to investigate the effects of various diluents (N2, CO2) with different radiative properties. Two systems w...