THREE-FLUID, THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SOLAR WIND MODEL WITH EDDY VISCOSITY AND TURBULENT RESISTIVITY
THREE-FLUID, THREE-DIMENSIONAL MAGNETOHYDRODYNAMIC SOLAR WIND MODEL WITH EDDY VISCOSITY AND TURBULENT RESISTIVITY
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DOI：
10.1088/0004-637x/788/1/43
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发表时间：
2014-05
期刊：
影响因子：
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通讯作者：
A. Usmanov;M. Goldstein;W. Matthaeus
中科院分区：
文献类型：
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作者：
A. Usmanov;M. Goldstein;W. Matthaeus
我们已经开发了一个三流体，三维磁流体动力学太阳风模型，其中包括湍流输送，涡动粘度，湍流电阻率，和湍流加热。太阳风等离子体被描述为一个共同运动的太阳风质子，电子和星际拾取质子的系统，每个物种都有单独的能量方程。在0.3 ~ 100 Au范围内（但仍在终端激波内），用时间松弛方法，在与太阳参考系共转的条件下，得到了与湍流输运方程耦合的太阳风平均方程的稳态数值解.模型方程包括电子热传导、库仑碰撞、星际氢原子的光电离及其与太阳风质子的电荷交换、拾取质子产生的湍流能量以及太阳风质子和电子的湍流加热效应。湍流传输模型基于雷诺分解和湍流现象，描述了湍流级联将波动能量转化为热量。除了使用单独的能量方程的太阳风质子和电子，一个显着的改进，我们以前的工作是，湍流模型现在使用的雷诺应力张量和平均湍流电场的涡粘性近似。该近似允许湍流模型考虑大尺度速度梯度对湍流的驱动。使用偶极近似的太阳磁场或天气太阳磁图从威尔科克斯太阳天文台分配边界条件在日冕底部，我们应用该模型来研究太阳风的全球结构及其三维特性，包括嵌入的湍流，加热，并在整个日光层加速。模型的结果进行了比较，等离子体和磁场观测风，太阳能电池板，旅行者2号航天器。
We have developed a three-fluid, three-dimensional magnetohydrodynamic solar wind model that incorporates turbulence transport, eddy viscosity, turbulent resistivity, and turbulent heating. The solar wind plasma is described as a system of co-moving solar wind protons, electrons, and interstellar pickup protons, with separate energy equations for each species. Numerical steady-state solutions of Reynolds-averaged solar wind equations coupled with turbulence transport equations for turbulence energy, cross helicity, and correlation length are obtained by the time relaxation method in the corotating with the Sun frame of reference in the region from 0.3 to 100 AU (but still inside the termination shock). The model equations include the effects of electron heat conduction, Coulomb collisions, photoionization of interstellar hydrogen atoms and their charge exchange with the solar wind protons, turbulence energy generation by pickup protons, and turbulent heating of solar wind protons and electrons. The turbulence transport model is based on the Reynolds decomposition and turbulence phenomenologies that describe the conversion of fluctuation energy into heat due to a turbulent cascade. In addition to using separate energy equations for the solar wind protons and electrons, a significant improvement over our previous work is that the turbulence model now uses an eddy viscosity approximation for the Reynolds stress tensor and the mean turbulent electric field. The approximation allows the turbulence model to account for driving of turbulence by large-scale velocity gradients. Using either a dipole approximation for the solar magnetic field or synoptic solar magnetograms from the Wilcox Solar Observatory for assigning boundary conditions at the coronal base, we apply the model to study the global structure of the solar wind and its three-dimensional properties, including embedded turbulence, heating, and acceleration throughout the heliosphere. The model results are compared with plasma and magnetic field observations on WIND, Ulysses, and Voyager 2 spacecraft.