Spatial Wall Shear Stress Gradient of Point Cloud using Least Square Approximation

Function to find Spatial Wall Shear Gradient of a Point Cloud

This function finds the spatial wall shear stress gradient at each node of a point cloud (nx3 array of x,y,z coordinates). It is intended for use with Ansys Fluent/CFD-Post data post processing. The least square approximation method for surface gradient is suggested by Anderson et al. 1994. The spatial wall shear stress gradient definition is given by Mut et al. 2010. The input argument pointcld_norm_mag_comp is an nx10 array (Xcoordinate Ycoordinate Zcoordinate NormalXcomponent NormalYcomponent NormalZcomponent MagnitudeWSS XcomponentWSS YcomponentWSS ZcomponentWSS) which is formatted as such because it is the format that CFD-Post gives when these values are selected for export. The input argument NN is number of neighboring nodes the user wishes to query for the least squares approximation.
Mut, Fernando, Rainald Löhner, Aichi Chien, Satoshi Tateshima, Fernando Viñuela, Christopher Putman, and Juan R. Cebral. "Computational Hemodynamics Framework for the Analysis of Cerebral Aneurysms." Int. J. Numer. Meth. Biomed. Engng. International Journal for Numerical Methods in Biomedical Engineering 27.6 (2010): 822-39. Web.

Anderson, W.kyle, and Daryl L. Bonhaus. "An Implicit Upwind Algorithm for Computing Turbulent Flows on Unstructured Grids." Computers & Fluids 23.1 (1994): 1-21. Web.