Hotspots are modelled by giving the initial material a non-zero volume fraction of products. The initial state in the products should be chosen carefully to be at the same pressure and temperature as the reactant.
For each reaction: flame_velocity (WXC++Realfunction2dfunction of density, temperature) For each material i in mixture: For each material j in mixture: common_surface_area_per_volume (WXC++Realfunction2dfunction of volume fraction i, volume fraction j)