镁-二氧化碳冲压发动机粉末燃料供应特性研究

In order to study the powder fuel supply system characteristics of Mg-CO₂ ramjet，a real-time monitoring system for the flow rate of powder，a high back-pressure simulation system and a powder injection visualization experiment system were built. The accuracy and stability of powder supply，powder supply state and powder injection characteristics under different carrier gas flow rates were analysed. Results show that the gas-solid two-phase flow cocked supply method ensured a stable and accurate supply of powder in the high back-pressure during simulated engine operation. The maximum measuring error of powder mass flow rate compared to the theoretical prediction is 4.8%. For the stability of the engine，the combustion experiments should be carried out in the stable stage of the carrier gas pressure. During this process，the mass flow rate of powder supply is only related to the piston speed and powder packing density. Within the studied carrier gas mass flow rate range，the carrier gas mass flow rate has no significant effect on the powder supply mass flow rate，but has a significant effect on the powder injection characteristics. Powder injection velocity increases linearly with the carrier gas mass flow rate，while the injection cone angle tends to decrease first and then increase with the carrier gas mass flow rate. Factors such as powder mixing，dispersion and engine combustion organization were considered. In order to improve the theoretical combustion performance of the model ramjet，the ratio of carrier gas flow rate to powder flow rate should be chosen to be around 0.68 in the later combustion experiments.