Hypersonic jets in astrophysical conditions: focus on spreading and asymmetric stability properties
Hypersonic jets in astrophysical conditions: focus on spreading and asymmetric stability properties
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DOI：
10.1088/1367-2630/16/8/085002
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发表时间：
2014-08
影响因子：
3.3
通讯作者：
M. Belan;D. Tordella;S. Ponte;A. Mignone;S. Massaglia
中科院分区：
文献类型：
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作者：
M. Belan;D. Tordella;S. Ponte;A. Mignone;S. Massaglia
年轻恒星发出的高马赫数射流具有显著的准直性、低开口角和抗不稳定性增长的弹性，尤其是不对称不稳定性。在最近的实验室实验中，Belan等人（2013 Astron）观察到与射流轴对齐的非对称三维低振幅长波的实例。天体物理学。为了探索高超声速射流的准直、扩散和不对称稳定性特性，我们在二维和三维空间进行了室内实验和数值模拟。我们发现，高马赫数的实验室流体动力射流保持准直，长度为数百个射流半径，并保持低开口角。这些发现得到了三维数值模拟的证实，在时间相关的情况下，在喷气入口施加不对称扰动。实验和受扰动的模拟射流都表现出长波长的非轴向模式，其生长不会破坏所考虑的区域内的射流。
High Mach number jets emanating from young stars show remarkable collimation, low opening angle and resilience against the growth of instabilities, especially the asymmetric ones. In recent laboratory experiments instances of asymmetric three-dimensional low amplitude long waves aligned with the jet axis were observed by Belan et al (2013 Astron. Astrophys. 554 A99). To explore the collimation, spreading, and asymmetric stability properties of hypersonic jets we carried out laboratory experiments and numerical simulations in two and three spatial dimensions. We find that laboratory hydrodynamic jets with high Mach numbers remain collimated, for hundreds of jet radii in length and maintain low opening angles. These findings are confirmed by 3D numerical simulations carried out after time-dependent, asymmetric perturbations are applied at the jet inlet. Both experimental and perturbed simulated jets show non-axial modes with long wavelengths, whose growth does not disrupt the jet in the domain considered.