Dr. Ghanshyam Vaghjiani

Dr. Ghanshyam Vaghjiani studies and evaluates reaction pathways pertinent to the understanding of numerous propellant decomposition and spacecraft-atmospheric processes. These include hypergolic ignition, laser initiated ignition, heterogeneous combustion, rocket exhaust plume emissions, Shuttle glow and space vehicle surface erosion. He designs, operates and maintains vacuum apparatuses, combustion and reaction chambers, lasers, spectrometers, computers and various laboratory digital electronic devices. Experimental findings are rationalized using modern chemical theories to construct reaction models which enable us to understand the mechanisms and to extrapolate from the laboratory to the conditions of real world applications.

His current interests are in understanding the self-ignition process in hypergolic propellants. When hypergolic liquids come in contact and mix, the initial heat release in the pre-ignition stage provides a mechanism for continued decomposition and/or vaporization of the fuel and the oxidizer into the gas-phase to a critical level such that the concurrent gas-phase exothermic reactions establish a flame front. The heat flux back into the condensed-phase reactants provides a continued flow of new gaseous materials to maintain thermal balance and sustained ignition. The detailed understanding of the fast interfacial reactions and dynamics, as well as thermo-physical processes such as thermolysis and vaporization is poor. Thus there is no rule-of-thumb for predicting, a priori, the hypergolicity of new fuels with existing oxidizers. Experimental verifications of the extent of reactivity in multiphase, inhomogeneous environments, and measurements of the ignition delay times are therefore necessary for identifying promising systems for new space propulsion applications. FTIR, VUV, and Mass spectroscopic techniques are being applied in the gas-phase, condensed-phase, and aerosolized mediums to ascertain the nature of the pre-ignition chemistry. Studies in ab initio quantum chemistry computations, molecular dynamics simulations, and chemical kinetics modeling are carried out to support his experimental findings.