Characterization of the ignition behavior of a microencapsulated hydrocarbon fuel-based monopropellant in combination with hydrogen peroxide

Abstract

Fuel-filled microcapsules can be mixed and stored with an oxidizer like hydrogen peroxide within the same tank. This allows a conventional bipropellant to be converted into a high-performance monopropellant that combines the advantages of both systems, such as low technical complexity, lower overall structural mass, and high specific impulse. The focus here is on hydrogen peroxide as an oxidizer. The development of a stable and storable dispersion of microencapsulated hydrocarbons in hydrogen peroxide gel has already been achieved. Prior to practical application, the developed monopropellant requires characterization, safety assessment, and investigation of the combustion behavior. Therefore, initial combustion tests were carried out in a strand burner setup, investigating the influence of various propellant parameters (hydrogen peroxide concentration, capsule size, ROF, fuel inside the capsules) and the influence of the combustion chamber pressure. In addition, the influence of thermal energy input and the use of various catalysts for ignition were investigated. Furthermore, initial safety-related tests about the impact sensitivity were carried out. The studies provide valuable insight into the combustion and thermal behavior of the propellant and represent an important step in its further development, also with regard to future hot fire tests.