Liquid monopropellant combustion in mesoscale vortex chamber

A study was conducted to demonstrate the usage of nitromethane (CH ₃NO₂), a liquid monopropellant, using vortex combustion chamber because of its potential to implement the wall film vaporization concept. A high pressure syringe pump was used to inject the liquid and a 2-mm-thick sapphire window capable of withstanding pressure up to 2.758 MPa was installed to provide optical access. The exhaust products were diluted with helium and analyzed using FT-IR spectrometer. A transducer connected to a port on the side wall of the combustor was installed to monitor the chamber pressure. The film combustion investigation was performed with combustion chamber operating on liquid nitromethane and little amount of oxygen at atmospheric pressure. It was observed that stable nitromethane combustion could be achieved when the chamber pressure increased more than 1.793 MPa (gauge).