论文标题
在钝鼻子震惊的停滞区中通过氢注入阻力控制
Drag Control by Hydrogen Injection in Shocked Stagnation Zone of Blunt Nose
论文作者
论文摘要
当前研究的主要动机是提出作为混合活性流控制技术的高压氢注入，以操纵大超声飞行期间钝鼻子前的流场。在停滞区的正确环境条件下，氢注射可以导致自我离子，并通过燃烧引起热量加热，并通过将弓形冲击推向上游，从而提供反激效应。半球形钝性鼻子的轴对称数值模拟以10000 PA压力和293 K温度的6马赫自由流动进行。比较了声音和超音速氢和空气注射，以减少与停滞压力比$ pr $和动量比（$ r_ {ma {ma} $）的阻力减少。在减速和类似的SPM流量方面，声音空气和氢注入方案显示出相似的性能，但是氢注入的质量流速比空气低3.76倍。超音速氢的注入$ M_J $ 2.94的行为与超音速空气注射不同，并且在较低的PR和LPM模式下，质量流量较低的较低PR和LPM模式下的阻力减少。此外，在较高的PR质量流速的情况下，空气注射在SPM模式下可实现40％的阻力减少。
The main motivation of the current study is to propose a high-pressure hydrogen injection as an hybrid active flow control technique in order to manipulate the flow-field in front of a blunt nose during hypersonic flight. Hydrogen injection can lead to self-igition under the right environment conditions in a stagnation zone, and may cause thermal heat addition through combustion and provide the counterjet effect together by pushing bow shock upstream. The axisymmetric numerical simulations for the hemispherical blunt nose are performed at a Mach 6 freestream flow with 10000 Pa pressure and 293 K temperature. The sonic and supersonic hydrogen and air injections are compared for drag reduction at the same stagnation pressure ratio $PR$ and momentum ratio ($R_{MA}$). The sonic air and hydrogen injection scenarios show similar performance in terms of drag reduction and similar SPM flow features, but hydrogen injection has a mass flow rate 3.76 times lower than air. Supersonic hydrogen injection at $M_j$ 2.94 behaves differently than supersonic air injection and can achieve up to 60 % drag reduction at lower PR and LPM mode with lower mass flow rate. Additionally, air injection achieves a drag reduction of 40 % in SPM mode at higher PR with very high mass flow rate.
