Accurate and robust adaptive mesh refinement for aerodynamic simulation with multi-block structured curvilinear mesh

摘要

A multi-block curvilinear mesh-based adaptive mesh refinement (AMR) method is developed to satisfy the competing objectives of improving accuracy and reducing cost. Body-fitted curvilinear mesh-based AMR is used to capture flow details of various length scales. A series of efforts are made to guarantee the accuracy and robustness of the AMR system. A physics-based refinement function is proposed, which is proved to be able to detect both shock wave and vortical flow. The curvilinear mesh is refined with cubic interpolation, which guarantees the aspect ratio and smoothness. Furthermore, to enable its application in complex configurations, a sub-block-based refinement strategy is developed to avoid generating invalid mesh, which is the consequence of non-smooth mesh lines or singular geometry features. A newfound problem of smaller wall distance, which negatively affects the stability and is never reported in the literature, is also discussed in detail, and an improved strategy is proposed. Together with the high-accuracy numerical scheme, a multi-block curvilinear mesh-based AMR system is developed. With a series of test cases, the current method is verified to be accurate and robust and be able to automatically capture the flow details at great cost saving compared with the global refinement. Copyright (c) 2015 John Wiley & Sons, Ltd.