粉末爆轰发动机的粉末燃料供应特性研究

Characteristics of Powder Fuel Supply for Powder Detonation Engine

关键词:  粉末爆轰发动机  粉末供应  粉末流化  流化均匀性  粉末装填

Key words:  Powder detonation engine  Powder supply  Powder fluidization  Fluidization uniformity  Powder filling

摘要:

为研究粉末爆轰发动机的粉末燃料供应特性，通过搭建一套流化仓内气固流动状态可视化的实验系统，采用称重传感器和静态压力传感器对粉末流化质量和流化仓内部压力进行实时监测，并采用电子天平精确测量粉末流化质量，对不同预压压力下粉末流化的时间均匀性，不同活塞速度下粉末流化的空间均匀性、粉末流化的流化能力特性展开分析。结果表明：粉末爆轰发动机的最佳工作时间为流化仓的压力稳定阶段和压力保持阶段；粉末在0.4~2MPa的预压压力下，其流化的时间均匀性几乎不变，且明显优于无预压下的粉末流化；粉末流化在空间上具有一定的均匀性，但其随着活塞速度的增大而逐渐减弱；粉末爆轰发动机燃料供应系统的气固比具有一个临界值，当实际气固比处于临界值以下时，会造成粉末来不及被流化气带走从而在流化仓中进行堆积最终堵塞流化仓；而当实际气固比高于临界值时，粉末流化能力随着活塞速度的增大而增大。

Abstract:

In order to study the powder fuel supply characteristics of powder detonation engine， a set of experimental system for visualizing the gas-solid flow state in the fluidization bin was built， the powder fluidization quality and the internal pressure of the fluidization bin were monitored in real time by using load cell and static pressure sensor， and the powder fluidization quality was accurately measured by electronic balance. In the process， the time uniformity of powder fluidization under different preload pressures， the spatial uniformity of powder fluidization under different piston speeds， and the characteristics of the fluidization ability of powder fluidization were analyzed. The results show that the best operating time of the powder detonation engine is at the pressure stabilization stage and the pressure maintaining stage of the fluidized chamber. The uniformity of fluidization time of the powder is almost unchanged under the pre-compression pressure of 0.4~2MPa， and it is obviously better than the powder fluidization without pre-compression. The powder fluidization maintains a certain uniformity in space， but it gradually weakens with the increase of the piston speed. The gas-solid ratio of the powder fuel supply system of the powder detonation engine has a critical value. When the actual gas-solid ratio is below the critical value， the powder will not be taken away by the fluidizing gas in time， so as to accumulate in the fluidized bin and finally block the fluidized bin. When the actual gas-solid ratio is above the critical value， the powder fluidization ability increases with the increase of the piston speed.