Global Simulations of Solar Dynamo using the Spectral Difference with Divergence Cleaning Algorithm
Abstract
The objective of this proposal is to further develop a three-dimensional (3D) spectral difference with di-vergence cleaning (SDDC) algorithm and combine it with the Compressible High-Order Unstructured Spectral difference (CHORUS) code for global simulations of solar dynamo with a new, robust, and effi-cient code, CHORUS++. The PI and his student published a baseline 2D SDDC algorithm in Chen and Liang, Astrophysical Journal, Vol 932, 2022. The divergence cleaning approach is based on an improved gener-alized Lagrange multiplier, which is consistent with the second law of thermodynamics. In this proposed project, CHORUS will be augmented to the sixth-order spectral difference (SD6) method from the origi-nal third-order scheme (SD3) for improved computational efficiency. A transfinite mapping technique will be implemented to annihilate geometric errors induced by the quadratic iso-parametric mapping of unstructured hexahedral elements. Additionally, transfinite mapping will help preserve angular momen-tum conservation of CHORUS solutions. In this proposal, the PI demonstrates the feasibility of the SDDC algorithm for resistive and Hall MHD models of a GEM magnetic reconnection problem through prelimi-nary results. The extension of the SDDC algorithm to 3D will be facilitated by the Hodge projection and diffusive cleaning technique. The feasibility of the proposed approach to predict nonlinear alpha-effect of a 3D dynamo is shown through direct numerical simulations of compressible MHD flow in a box. Fur-thermore, the dynamics of global-scale dynamo in a rotating spherical shell will be studied in detail by CHORUS++ to reproduce the basic properties of large-scale convective flows and solar-like magnetic cy-cle. Moreover, the PI will actively disseminate this new CHORUS++ code to the space weather commu-nity through participation in Solar Heliospheric and INterplanetary Environment (SHINE) workshops and summer visits to the National Center for Atmospheric Research (NCAR) and an Air Force Research Lab.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Mar 07, 2024
- Source ID
- FA95502310596
Entities
People
- Chunlei Liang
Organizations
- Air Force Office of Scientific Research
- Clarkson University
- United States Air Force