2-D local hp adaptive isogeometric analysis based on hierarchical Fup basis functions

In this paper, 2-D hp local adaptive procedure is developed based on Control Volume Isogeometric Analysis (CV-IGA) and Hierarchical Fup (HF) basis functions. Contrary to the most common truncated hierarchical splines, HF enables local hp adaptation because higher resolution levels do not include only basis with smaller compact support or higher frequencies, but also with higher order. Consequence of this property is spectral convergence of the proposed adaptive algorithm which is presented on classical benchmarks such as L-shape benchmark and advection dominated problems. Even in non-smooth problems, spectral convergence is achieved contrary to the application of uniform grid. CV-IGA ensures local and global mass conservation which is potentially very important for fluid mechanics problems. 2-D proposed algorithm chooses regular control volumes in parametric space at all resolution levels closely related to the Greville points (vertices) of basis functions. Therefore, methodology is very simple requiring only overlapping of control volumes in the areas where different levels are connected, while its computational cost lies between Galerkin and collocation formulations.