Collaborative Project: On the Origin of Stellar Activity: Generation and Propagation of Wave Energy in the Surface Layers of Late-Type Dwarfs

合作项目：恒星活动的起源：晚型矮星表层波能的产生和传播

• 批准号: 9115191
• 负责人: Zdzislaw Musielak
• 金额: $ 5.5万
• 依托单位: University of Alabama in Huntsville
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-12-01 至 1994-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9115191&HistoricalAwards=false
• 关键词: Collaborative; Project; Origin; Stellar; Activity

Atmospheric turbulent energy degrades itself into smaller scales of motion until its energy is converted entirely to heat, sound, and light. The convective granular motions of the outer envelope of the Sun and other cool stars are thought to convert their energy into acoustical energy, which is thought to play a key role in the heating of the outer atmosphere (chromosphere) of the Sun. Just how important this role may be is still controversial as an error has been found in important assumptions that have been made in the past to evaluate acoustical heating in the solar chromosphere. The Principal Investigator and his collaborator, F. Cattaneo, plan an extensive set of computer numerical simulations in which the excitation of acoustical energy will be computed from a set of equations describing turbulence in a three-dimensional compressional fluid. In addition, their experiments will include the effects of turbulence in plasma containing tubes of magnetic flux, such as are thought to be important on the Sun's surface. The computations of acoustic energy will be used to compute heating from sound waves which can be directly compared to the cooling of the chromopheres of the Sun and other stars from X-ray observations. It is anticipated that this work will put the estimates of acoustical energy in star's atmospheres on a firm, experimental basis and should permit estimates of the minimum amounts of mass that stars can lose through a heating of their outer atmospheres. In addition, it may lead to applications of the dissipation of energy from loud acoustical sources on the Earth (e.g. jet engines).

大气湍流能量将其自身分解为更小的尺度 直到它的能量完全转化为热，声音， 和光。 外层包层的对流颗粒运动 太阳和其他冷恒星的能量 转化为声能，这被认为在 太阳外层大气（色球层）的加热。 只是 这一作用究竟有多重要，作为一个错误， 已经在一些重要的假设中被发现， 过去用于评估太阳色球层的声学加热。 首席研究员和他的合作者，F。卡塔内奥，计划一下 一套广泛的计算机数值模拟，其中 声能的激发将从一组 三维湍流方程 挤压流体 此外，他们的实验将包括 等离子体中的湍流效应 通量，如被认为是重要的太阳表面。 声能的计算将用于计算加热 从声波中可以直接比较到 太阳和其他恒星的色球 意见。 预计这项工作将使 对星星大气层中声能的估计， 实验基础上，并应允许估计的最低限度 恒星通过加热它们的能量 外大气层 此外，它还可能导致 大声源的能量耗散 地球（如喷气发动机）。