TY - GEN
T1 - Ignition behavior of novel hypergolic materials
AU - Chowdhury, Arindrajit
AU - Thynell, Stefan
AU - Wang, Shiqing
PY - 2009/12/1
Y1 - 2009/12/1
N2 - The complex interplay of various physical and chemical phenomena occurring during the ignition of dicyanamide-based novel ionic liquids as fuels and nitric acid as the oxidizer was probed. The pre-ignition condensed phase chemistry was analyzed by a modified confined rapid thermolysis setup under isothermal conditions. The major gases accumulating in the ignition zone were found to be CO2, N2O, H2O, and HNCO, within the temperature range 30-50°C. A reaction mechanism initiated by an exothermic neutralization, followed by formation of cyano-nitro-urea and dinitrobiuret, leading to the smaller molecular weight gases, was formulated. A conventional drop test setup was utilized to determine the temperatures in the gas phase in both the pre-ignition and post-ignition stages. High speed videos of the ignition event were acquired to further aid in the resolution of the separate events leading to ignition as a droplet of fuel collides with a pool of oxidizer. The videos showed the expulsion of small droplets of condensed phase matter into the ignition zone due to vigorous condensed phase reactions prior to the formation of the ignition kernel. The global ignition delay for the ionic liquid 1-ethyl-3-methyl-imidazolium dicyanamide (EmimDCA) was approximately doubled from 35 ms by substituting white fuming nitric acid (WFNA) with 90% HNO3 as the oxidizer.
AB - The complex interplay of various physical and chemical phenomena occurring during the ignition of dicyanamide-based novel ionic liquids as fuels and nitric acid as the oxidizer was probed. The pre-ignition condensed phase chemistry was analyzed by a modified confined rapid thermolysis setup under isothermal conditions. The major gases accumulating in the ignition zone were found to be CO2, N2O, H2O, and HNCO, within the temperature range 30-50°C. A reaction mechanism initiated by an exothermic neutralization, followed by formation of cyano-nitro-urea and dinitrobiuret, leading to the smaller molecular weight gases, was formulated. A conventional drop test setup was utilized to determine the temperatures in the gas phase in both the pre-ignition and post-ignition stages. High speed videos of the ignition event were acquired to further aid in the resolution of the separate events leading to ignition as a droplet of fuel collides with a pool of oxidizer. The videos showed the expulsion of small droplets of condensed phase matter into the ignition zone due to vigorous condensed phase reactions prior to the formation of the ignition kernel. The global ignition delay for the ionic liquid 1-ethyl-3-methyl-imidazolium dicyanamide (EmimDCA) was approximately doubled from 35 ms by substituting white fuming nitric acid (WFNA) with 90% HNO3 as the oxidizer.
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M3 - Conference contribution
AN - SCOPUS:77957856709
SN - 9781563479762
T3 - 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
BT - 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
T2 - 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference and Exhibit
Y2 - 2 August 2009 through 5 August 2009
ER -