An experimental study on the effects of an applied external electric field on the combustion behavior of solid fuels and solid propellants has been conducted. In an opposed flow burning configuration, application of an electric field was shown to extinguish a paraffin fuel and gaseous oxygen flame over a broad range of operating conditions. When subjected to the electric field, burning paraffin fuel strands were found to extinguish at various axial locations relative to the exit of the oxidizer gas jet. Extinguishment location was found to be a function of field strength as well as electrode surface area, while changes in polarity did not significantly alter the results. In addition, the combustion behaviors of two composite solid rocket propellants were studied while subjected to an external electric field. Both propellants were based on HTPB/AP combinations, with one propellant containing aluminum and the other being non‐aluminized. Application of an electric field to the composite solid rocket propellant strands demonstrated decreases in propellant burning rate under all operating conditions for both propellants including changes in polarity. The flame structure of the aluminized propellant was examined closely as the luminosity, flame length, and flame width varied significantly with field strength and burning location of the strand relative to the electrodes.

An experimental investigation of the effect of fuel-to-oxidant ratio and reactant composition on the performance of a lab-scale gaseous rocket engine was performed. The senior design project involved the design, fabrication, and testing of a laboratory scale gaseous reactant rocket engine. A simplified zeroth order combustion model was developed to provide guidance for the design of the rocket system. Conservation equations along with chemical equilibrium results were the fabric of the model development. Peak chamber pressures as a function of reactant delivery rates and nozzle diameters were the primary output of the code. Experiments were conducted as a function of chamber pressure and equivalence ratio. For an equivalence ratio of 1, CH 4 mass flow of 1.26 g/s and oxygen flow rate of 4.48 g/s, the measured chamber pressure was nearly 160 psig having a combustion efficiency of 85%. Theoretical pressure-time profiles were compared to empirically-obtained profiles and the peak pressures agreed well. Combustion efficiencies across a broad range of equivalence ratios were found to be approximately 80%±6. Nomenclaturec = chamber = mass flow rate [ kg/s] C* th = theoretical characteristic velocity [m/s] η = efficiency A t = throat area [m 2 ] st = stoichiometric P = pressure [psi] V = volume [m 3 ] R = gas Constant [kJ/kg-K] T = temperature [K] G ox = oxidizer mass flow rate [g/s] O/F = oxidizer-to-fuel ratio = equivalence ratio D c = chamber diameter [m] L c = chamber length [m] L* = characteristic chamber length [m] MW = molecular weight [kg/kmol] = specific heat ratio function C d = discharge coefficient t = time [s]