In this paper we describe a simple numerical approach which allows to study the structure of steady-state axisymmetric relativistic jets using one-dimensional time-dependent simulations. It is based on the fact that for narrow jets with $v_{z}\approx c$ the steady-state equations of relativistic magnetohydrodynamics can be accurately approximated by the one-dimensional time-dependent equations after the substitution $z=ct$ . Since only the time-dependent codes are now publicly available this is a valuable and efficient alternative to the development of a high-specialised code for the time-independent equations. The approach is also much cheaper and more robust compared to the relaxation method. We tested this technique against numerical and analytical solutions found in literature as well as solutions we obtained using the relaxation method and found it sufficiently accurate. In the process, we discovered the reason for the failure of the self-similar analytical model of the jet reconfinement in relatively flat atmospheres and elucidated the nature of radial oscillations of steady-state jets.

中文翻译：

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固定相对论射流。

在本文中，我们描述了一种简单的数值方法，该方法允许使用一维时变模拟研究稳态轴对称相对论射流的结构。这是基于这样的事实，对于替换为$ z = ct $的一维时间相关方程，对于具有$ v_ {z} \ approx c $的窄喷射流，相对论磁流体力学的稳态方程可以精确地近似。由于现在只有时间相关的代码可以公开获得，因此，这是开发与时间无关的方程式的高专业代码的一种有价值且有效的替代方法。与松弛方法相比，该方法也更便宜，更耐用。我们针对文献中发现的数值和解析解以及使用松弛法获得的解进行了测试，发现该技术足够准确。在此过程中，我们发现了在相对平坦的大气中重新约束射流的自相似分析模型失败的原因，并阐明了稳态射流的径向振荡性质。