Deformation Consistency Problem in the Structured Grid Motion Method Based on Radial Basis Functions and Transfinite Interpolation

A deep analysis was implemented on the distortion of space grid edge as well as the crossover of grid cells induced by deformation consistency problem in the structured grid motion method based on radial basis functions and transfinite interpolation(RBF_TFI).Then an improved RBF_TFI method for structured grid motion was presented in accordance to the analysis results.Firstly,the reason of deformation consistency problem in different center selection schemes was investigated in terms of deformed grid quality,displacement errors at edge-intersection points and space grid edge distortion through the case that the HIRENASD wing model has a 30-degree rotation around the y axis.Secondly,the space grid edges connected to the solid surface are defined as boundary edges and a cubic spline interpolation is adopted to update the coordinates of the grid points on these edges.Finally,the HIRENASD example was used once again to estimate the effects of the improved RBF_TFI method.The results of grid deformation show that the improved RBF_TFI method can remove the distortion of space grid edges caused by deformation consistency problem and avoid generating deformed grid cells with crossover and negative volume.