Investigations On The Characteristics Of Ignition And Self-maitenance Combustion Of Powdered Fuel Ramjet Charged With A Mixture Of Magnesium And Boron

Powdered fuel ramjet holds both the advantages of the solid ducted rocket which are simple structure, convenient for maintenance, the stability of combustion and the advantages of the liquid fuel ramjet which are altered fuel mass, high combustion efficency, high impulse. And because of this, there are good perspectives on the application of the powdered fuel ramjet in the high-performance missiles.The aim of this dissertation is to apply the high-energy boron powder which is coated by AP to powdered fuel ramjet, to achieve the ignition and self-maintenance combustion of powder fuel ramjet, to analyse the impact factors on the ramjet combustion efficiency and to provide a reference for the further study on the enhancement of the ramjet combustion efficiency.A igniton model was established for boron particle coated by AP in this dissertation and is validated with the data from another paper. Then the impact on the ignition time of boron particle coated by AP was investigated in terms of particle diameter, AP fraction of coated boron particle, atmosphere temperature and radiation temperature.The ignition and structure type of test ramjet was determined by numerical simulation, and the direct-connect tests proved the feasibility of igniton and self-maintenance combustion of ramjet. Phenomenon during the direct-connect tests confirmed that boron powder coated by AP was ignited successfully in the chamber.The impact, which was terms of the injection forms and proportionof the primary and the secondary air flow, the composition, particle diameter and jet volecity of powdered mixture fuel, on the ramjet combustion efficiency was investigated. Then the combustion oscillation during the direct-connect tests was analysed, and modified measures were taken to restrain the combustion oscillation.