SFB 963: Astrophysical Flow Instabilities and Turbulence

在天体物理学和宇宙学中，流体流动发生在大范围的尺度和非常不同的条件下，从恒星和行星的致密内部到高度稀薄的星系际介质。这些流动都有一个共同的事实，即它们通常是湍流的，即在空间和时间上都高度无序。大多数天体物理流动发生在驱动力产生速度和压力的大波动的条件下，对能量和质量的传输产生重要影响。湍流是各种地球和天体物理系统结构和演化的关键过程之一。天体物理学的湍流和不稳定性与旋转、对流和磁场有关。天体物理学湍流的普遍性将行星或恒星内部的物理学与原行星或星系盘以及星系外的星系际气体联系在一起。例如，湍流的角动量输运是一个核心问题，必须回答才能理解星系或恒星是如何形成的，原行星盘是如何演化的，金属是如何在星际和星系间介质中混合的，或者恒星和行星是如何建立差动旋转的。通过湍流发电机过程的磁场放大在行星、恒星和星系中无处不在。由于尘埃颗粒或原行星盘中新形成的行星引起的不稳定性的开始控制着演化结构的性质。我们可以观察到恒星、行星和星系与其环境之间的各种相互作用，从而导致能量和（角）动量的交换。这份汇编突出了巨大的潜力和前景的合作努力，调查共同的基本物理过程。我们的项目组合将使我们能够了解湍流磁场放大，湍流和旋转流体的不稳定性，以及湍流和不稳定性与辐射，引力或尘埃粒子的相互作用，从而回答有关星系，恒星和行星的形成和演化的基本问题。

In astrophysics and cosmology, fluid flow occurs on a large range of scales and under very different conditions, from the dense interior of stars and planets to the highly rarefied intergalactic medium. These flows share the fact that they are generally turbulent, i.e. highly disordered both in space and time. Most astrophysical flows occur under conditions where the driving forces generate large fluctuations in velocity and pressure with important consequences for the transport of energy and mass. Turbulence is one of the key processes for the structure and evolution of a large variety of geo- and astrophysical systems. Astrophysical turbulence and instabilities occur in connection with rotation, convection and magnetic fields. The universality of astrophysical turbulence interlinks the physics of the interior of planets or stars with protoplanetary or galactic disks, as well as the intergalactic gas outside of galaxies. For example, angular momentum transport by turbulence is a central question that must be answered to understand how galaxies or stars form, how protoplanetary disks evolve, how metals are mixed in the interstellar and intergalactic medium, or how differential rotation is established in stars and planets. Magnetic field amplification through turbulent dynamo processes is ubiquitous in planets, stars and galaxies. The onset of instabilities due to dust particles or newly formed planets in protoplanetary disks controls the properties of the evolving structures. We can observe a variety of interactions between stars, planets and galaxies with their environment leading to the exchange of energy and (angular-)momentum. This compilation highlights the enormous potential and perspective of a collaborative effort to investigate the common underlying physical processes. Our combination of projects will enable us to understand aspects of turbulent magnetic field amplification, turbulence and instabilities of rotating fluids, and in the interaction of turbulence and instabilities with radiation, gravitation or dust particles and hence answer fundamental questions about the formation and evolution of galaxies, stars and planets.