Analytical solutions and artificial neural network approximations for sand ripples in granular media
摘要
This study investigates nonlinear sand-ripple formation in granular media using a hybrid analytical–computational framework. Three nonlinear partial differential equation models are examined, incorporating key physical mechanisms such as surface diffusion, dispersion, and nonlinear steepening. Exact travelling–wave and solitary–wave solutions are derived via an ansatz–based analytical method, providing clear insight into ripple stability and morphology. The analytical solutions are subsequently utilized as training data for an artificial neural network approximation (ANNA), allowing a mesh-free characterization of the solution space. These two ANNA therefore both do well to a level of order