Wrapping a Rectangular Grid Around a Wing — Curvilinear Coordinate Transforms and Grid Metrics
·6 min read
On a wavy mesh the Jacobian runs from 0.62 to 1.38 and stays positive. Write the flux as y_η and the freestream residual falls to about 1e-16.
Quadtree AMR — Letting the Mesh Grow Where It Needs To
·7 min read
Level-7 uniform needs 128 cells; one Gaussian keeps 41 leaves, about 32 percent. A quadtree, slope threshold tau, and a 2:1 rule decide which cells split.
Solving Wall Distance in O(N log N): Eikonal Equation and Fast Marching
·7 min read
Ten million cells and half a million walls mean five trillion distance checks. Fast Marching solves that wall distance as an Eikonal problem in O(N log N).