R. Mittal has developed during her Ph.D. at IIT Delhi and LMD a positive definite advection
scheme on hexagonal-icosahedral grids (Mittal et al., 2007). It is a
finite volume scheme where the hexagons are the control volumes.
As in LMD-Z, monotonicity results from the use of
slope limiters (Hourdin & Armengaud, 1999).
Test Case : Deformational Flow
Numerical solution with 10242 cells