Dust in the Wind: Dynamics of Dusty Fluids on Interstellar, Stellar, and Planetary Scales

尘埃颗粒是微小的颗粒，从烟雾状的烟灰和微观的沙粒状颗粒到晶体，几乎对所有天体物理学都至关重要。这些颗粒包含了宇宙中所有重元素的很大一部分，因此代表了最终构成行星和我们的“积木”。天文学家早就知道尘埃与行星、恒星和星系之间的空间中的氢气和氦气混合，但对“尘埃流体”的动力学仍然知之甚少。了解尘埃颗粒的相互作用是恒星之间物质和恒星之间气体“再循环”的重要模型。 为了解决这些问题，研究人员将产生新的，大规模并行的公共计算代码。该软件也将适用于更一般的工程和湍流/空气动力学应用。调查员计划为本科生，高中生和高中教师提供暑期研究机会。这项工作还将为外展计划，公共演讲和天文馆表演生成动画和可视化。研究小组最近发现了以前未知的不稳定性，这些不稳定性可以重写大部分关于尘埃颗粒如何随时间变化并改变行星和恒星形成的传统智慧。学生将运行计算机模拟，结合所有相关过程，自洽地模拟这些问题，并捕捉这些不稳定性的行为。这是由研究人员开发的新一代大规模计算机代码实现的。 这些代码数值求解与尘埃和磁场和辐射相互作用的流体动力学方程。他们将为行星盘、行星性质、恒星变化和恒星周围气体结构开发新的可测试预测。这项工作将从根本上帮助我们理解行星如何形成，恒星如何随时间变化，恒星和行星--以及我们的化学组成部分--该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

Dust grains are tiny particles, ranging from smog-like soots and microscopic sand-like grains to crystals, are of fundamental importance to almost all astrophysics. These grains contain a huge fraction of all the heavy elements in the Universe, and as such represent the "building blocks" that ultimately make up the planets and us. Astronomers have long known that dust is mixed with Hydrogen and Helium gas in the space between the planets, stars, and galaxies, but the dynamics of "dusty fluids" remain poorly understood. Understanding the interactions of dust grains is important models of "recycling" of material between stars and the gas between stars. To address these issues, the investigator will produce new, massively parallel, public computational codes. This software will also be applicable to more general engineering and turbulence/aerodynamic applications. The investigator plans summer research opportunities for undergraduates, high school students, and high school teachers. This work will also generate animations and visualizations for outreach programs, public talks, and planetarium shows. The investigator’s group has recently discovered previously unknown instabilities that can re-write much of the conventional wisdom about how dust grains change with time and alter the formation of planets and stars. Students will run computer simulations incorporating all the relevant processes to model these problems self-consistently and capture the behaviors of these instabilities. This is enabled by a new generation of massive computer codes the investigators have developed. These codes numerically solve the equations of fluid dynamics interacting with dust and magnetic fields and radiation. They will develop novel testable predictions for planetary disks, planet properties, variations of stars, and structure of the gas around stars This work should contribute fundamentally to our understanding how planets form, how stars change with time, and where stars and planets -- and our chemical building blocks -- come from.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.