Exploratory Testing of the MBB 10 N Bipropellant Engine. Volume 2: Preliminary Exhaust Plume Investigations

摘要

The contaminants and their distributions in the exhaust plume of a MBB 10 N bipropellant thruster were investigated during pulse mode firings. The principal contaminant is monomethylhydrazine nitrate, a condensate of the combustion product. Design parameters affecting pulse performance and life capability are the injector manifold volume and injector/combustion chamber compatibility. Thruster pulse duration strongly influences performance and contamination rate due to incomplete combustion during ignition and shutdown phases. Condenseous reaction products in the plume can cause strong electrostatic charges. Propellant impurities have a direct impact on the erosive and abrasive effect of the thruster exhaust plume within a cone of 10 deg half cone angle from the nozzle center line.