Development of Kelvin–Helmholtz (KH) instability in solar coronal jets can trigger the wave turbulence considered as one of the main mechanisms of coronal heating. In this review, we have investigated the propagation of normal MHD modes running on three X-ray jets modeling them as untwisted and slightly twisted moving cylindrical flux tubes. The basic physical parameters of the jets are temperatures in the range of 5.2–8.2 MK, particle number densities of the order of  cm⁻³, and speeds of 385, 437, and 532 km s⁻¹, respectively. For small density contrast between the environment and a given jet, as well as at ambient coronal temperature of 2.0 MK and magnetic field around 7 G, we have obtained that the kink () mode propagating on moving untwisted flux tubes can become unstable in the first and second jets at flow speeds of ≅348 and 429 km s⁻¹, respectively. The KH instability onset in the third jet requires a speed of ≅826 km s⁻¹, higher than the observed one. The same mode, propagating in weakly twisted flux tubes, becomes unstable at flow speeds of ≅361 km s⁻¹ for the first and of 443 km s⁻¹ for the second jet. Except the kink mode, the twisted moving flux tube supports the propagation of higher () MHD modes that can become unstable at accessible jets’ speeds.

中文翻译：

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模拟软X射线太阳射流中的Kelvin–Helmholtz不稳定性

太阳日冕射流中Kelvin–Helmholtz（KH）不稳定性的发展会触发被认为是日冕加热的主要机制之一的波湍流。在这篇综述中，我们研究了在三个X射线射流上运行的正常MHD模式的传播，将其建模为未扭曲和轻微扭曲的移动圆柱通量管。射流的基本物理参数是温度在5.2–8.2 MK范围内，粒子数密度为 cm ^-3左右，速度分别为385、437和532 km s ^-1。对于环境和给定射流之间的小密度对比，以及在2.0 MK的日冕温度和7 G左右的磁场下，我们得出了扭结（在未扭动的通量管上传播的模式可能分别在jet 348和429 km s ^-1的流速下在第一和第二射流中变得不稳定。在第三喷射的KH失稳需要的速度≅ 826公里S ^-1，比观察到的一个更高。在弱扭曲的通量管中传播的相同模式在第一个射流的≅361km s ^-1和第二个射流的443 km s ^-1的流速下变得不稳定。除扭结模式外，扭曲的移动通量管还支持更高（）的MHD模式的传播，这些模式在可达到的射流速度下可能变得不稳定。