Secondary Combustion Test Of Boron-containing Propellant And Its Influence

The primary rich combustion gas generated by the boron-containing oxygen-depleted propellant and the incoming air entering the intake port are fully mixed in the secondary combustion chamber of the solid rocket ramjet engine and then reburned.While increasing the thermal energy of the gas,it will cause the ablation of the thermal insulation layer,thereby reducing the thermal protection capability of the engine.This paper firstly completes the design of the system required for the experimental study of the secondary combustion performance of the supplementary combustion chamber.Then,the system is used to conduct experimental research on the working process and performance of the engine,and the ablation characteristics of the thermal insulation layer are analyzed using a 3D scanner.Finally,numerical methods are used to analyze the gas-solid two-phase combustion process in the supplementary combustion chamber.The specific research contents and conclusions are as follows:(1)Combined with the needs of the solid rocket ramjet direct-connection test,the design of the large-flow air supply system,the heating system and the preliminary design of the data acquisition system are completed.The ablation of the thermal insulation layer of the secondary combustion of the solid rocket ramjet engine was experimentally measured by using the designed ground direct connection experimental system.Experimental results show that: 1)The designed test system meets the test requirements of large-flow solid rocket ramjet;2)For the solid rocket ramjet studied in this paper,the thermal insulation layer downstream of the outlet of the intake port is seriously ablated,and particles formed by particles appear in the tail of the secondary combustion.The "gully" shape formed by erosion;(2)By analyzing the secondary combustion condensed phase products in the supplementary combustion chamber,the ablation and combustion efficiency of the adiabatic layer are studied.The results show that: in the supplementary combustion chamber,the main components of the secondary combustion condensed phase products are boron oxide,magnesium oxide,boron particles,boric acid,carbon The morphological characteristics of the condensed phase products are that the average diameter of the particles decreases gradually as they move away from the head of the supplementary combustion chamber,and the combustion completion degree of solid particles reaches the highest at the rear of the supplementary combustion chamber;the content of boron oxide increases with the thermal insulation layer of the supplementary combustion chamber.The increase in the degree of "gully" on the inner wall surface increases;(3)In this paper,the numerical analysis of the two-phase flow and combustion process of boron-containing particle-rich gas in the supplementary combustion chamber is carried out.The research results show that: the boron particles in the rich combustion gas generated by the gas generator undergo a violent chemical reaction near the intake port;the boron particles collide with the wall surface of the supplementary combustion chamber,which increases the erosion of the thermal insulation layer;the wall surface of the supplementary combustion chamber The high temperature area moves backward to the rear of the supplementary combustion chamber.