高超声速进气道内粉末燃料喷注及流动控制特性研究

Characteristics of Powder Fuel Injection and Flow Control in Hypersonic Inlet

关键词:  高超声速进气道  金属粉末燃料  波系控制  喷注  掺混

Key words:  Hypersonic inlet  Metal powder fuel  Wave system control  Injection  Blending

摘要:

为了提高进气道性能以及金属粉末燃料的掺混效率，本文将粉末燃料的喷注提前到高超声速进气道内完成。以铝粉作为喷注燃料，氮气作为流化气，基于连续相-离散相（CFD-DPM）耦合模型，采用数值模拟的方法重点研究了在进气道内喷注粉末燃料对进气道性能和颗粒掺混度的影响。结果表明：在超额定状态下通过在外压段喷注粉末燃料进行波系控制，可以用比气体射流控制更低的喷注压力实现激波贴口的效果，在来流马赫数Ma₀=6时，与气体射流控制相比，两个喷嘴的入口总压分别降低了17.9%和31.8%。与常规定几何进气道相比，经过粉末燃料喷注后进气道的综合性能有了显著的提高，低马赫数下流量系数提高24%以上，总压恢复系数也明显提高，并且实现了粉末燃料与氧气的充分掺混。

Abstract:

In order to improve the performance of the inlet and the blending efficiency of metal powder fuel， the injection of powder fuel is advanced into the hypersonic inlet. Aluminium powder is used as the powder fuel and nitrogen is used as the fluidizing gas. Based on the continuous phase-discrete phase （CFD-DPM） coupling model， the numerical simulation method is used to focus on the effects of the injection of powder fuel in the inlet on the performance of the inlet and the degree of particles blending. The results show that the wave system can be controlled by injecting powder fuel in the external pressure section in the over-rated state， and the effect of shock-on-lip can be achieved with lower injection pressure than the gas jet control. When the incoming flow Mach number Ma₀=6， the total inlet pressure of the two nozzles is reduced by 17.9% and 31.8% respectively compared with gas jet control. Compared with the conventional fixed geometry inlet， the overall performance of the inlet has been significantly improved after powder fuel injection. The flow coefficient at low Mach number increased by more than 24%， the total pressure recovery coefficient is also significantly improved， and the powder fuel and oxygen are fully blended.