Figure 5: Comparison between DEM and Turing model.
From: Self-charging of identical grains in the absence of an external field
(a) Transient from DEM (blue) and Turing simulations (magenta); both ordinate axes are logarithmic; DEM parameters: χe = 0.9, η = 0.2; Turing parameters: A = 2.25, A − B = −4 (with diffusive terms removed as described in text). (b) Color coded (blue: negative, red: positive) charges in both models using DEM parameters χe = 1, η = 1, and Turing parameters A = 0.0005 and A − B = −0.0001; DEM shows slice through center of simulation, and Turing results show height average (left) and 3D view (right) of charges. (c) The same views as panel (b), but using DEM parameters χe = 1, η = 0.6, and Turing parameters A = 0.0005 and A − B = −0.0005. The spotted patterns here are typical, with wavelength that decreases as A and A − B grow.
