Burning behaviour of ADN formulations

The application of ADN for an effective oxidizer of propellants and explosi ves requires a detailed knowledge of the burning behaviour. The physical an d chemical mechanisms of the combustion depend on pressure. Especially prof iles of temperature and species in the flame are important to design propel lant formulation of high performance and low signature of the rocket plume. In the presented study, pure ADN and ADN/paraffin mixtures were investigat ed as strands in an optical bomb at pressures of 0.5 MPa to 10 MPa. The app lication of non-intrusive combustion diagnostics for the investigation of f ast burning energetic materials allowed the measurement of burning rates an d profiles of temperature and gas components at various distances above the burning propellant surface. The burning rate was determined by using a vid eo system and a special frame analysis. The acquisition and analysis of emi ssion spectra in the UV/VIS allowed the investigation of rotational tempera tures, the determination of particle temperatures and the identification of transient flame radicals. The vibrational temperatures of final combustion products resulted from band spectra emitted in the near and mid infrared s pectral range. Burning rates of 5 mm/s to 70 mm/s were recorded showing a m esa/plateau-effect in the pressure range of 4 MPa to 7 MPa. The UV/VIS spec tra indicated an emission from OH, NH and CN radicals. The strong emission of OH bands of the ADN/paraffin mixture allowed the investigation of rotati onal temperatures with a mean value of 2700 K which is closely below the ad iabatic flame temperature of 2950 K. Additionally, one-dimensional intensit y profiles of the flame radicals were measured. As combustion end products H2O, CO, CO2 and NO were found. NO could only be detected at a distance up to 2 mm above the propellant surface. The measured CO/CO2 fraction was high er as 10/1. Water could only be detected far above the propellant surface.