Related papers: Modelling a Dune Field
Aeolian sand dunes originate from wind flow and sand bed interactions. According to wind properties and sand availability, they can adopt different shapes, ranging from huge motion-less star dunes to small and mobile barchan dunes. The…
The dune skeleton model is a reduced model to describe the formation process and dynamics of characteristic types of dunes emerging under unidirectional steady wind. Using this model, we study the dependency of the morphodynamics of…
We model formation and evolution of transverse dune fields. In the model, only the cross section of the dune is simulated. The only physical variable of relevance is the dune height, from which the dune width and velocity are determined, as…
We apply a mean-field model of interactions between migrating barchan dunes, the CAFE model, which includes spontaneous calving, aggregation, fragmentation, and mass-exchange, yielding a steady-state size distribution that can be resolved…
The simplest type of dune is the transverse one, which propagates with invariant profile orthogonally to a fixed wind direction. Here we show numerically and with a linear stability analysis that transverse dunes are unstable with respect…
Corridors of size-selected crescent-shaped dunes, known as barchans, are commonly found in water, air, and other planetary environments. The growth of barchans results from the interplay between a fluid flow and a granular bed, but their…
A simple model for the dynamics of dunes associated with vegetation is proposed. Using the model, formation processes of transverse dunes, parabolic dunes and elongated parabolic dunes according to two environmental factors: i)the amount of…
We investigate experimentally the short-range interactions occurring between two subaqueous barchans. The experiments were conducted in a water channel of transparent material where controlled grains were poured inside, and a camera placed…
This paper presents an experimental investigation of moving grains over subaqueous barchan dunes that consisted of spherical glass beads of known granulometry. Prior to each test run, a pre-determined quantity of grains was poured inside a…
Barchan dunes, or simply barchans, are crescent-shaped dunes found in diverse environments such as the bottom of rivers, Earth's deserts and the surface of Mars. In a recent paper [Phys. Rev. E 101, 012905 (2020)], we investigated the…
We investigate the behavior of subaqueous barchans reaching dune-size obstacles by carrying out experiments where we varied the obstacle shape and size, the flow strength, and the grains' properties. We found that a subaqueous barchan can…
We propose a minimal model for aeolian sand dunes. It combines an analytical description of the turbulent wind velocity field above the dune with a continuum saltation model that allows for saturation transients in the sand flux. The model…
Barchans are eolian dunes of crescent shape found on Earth, Mars and other celestial bodies. Among the different types of barchan-barchan interaction, there is one, known as chasing, in which the dunes remain close but without touching each…
We explore a simplified class of models we call swarms, which are inspired by the collective behavior of social insects. We perform a mean-field stability analysis and perform numerical simulations of the model. Several interesting types of…
Dune fields are commonly associated with periodic patterns that are among the most recognizable landscapes on Earth and other planetary bodies. However, in zones of limited sediment supply, where periodic dunes elongate and align in the…
We use FLUENT to calculate the wind profile over barchans and transverse dunes. The form of the streamlines of flow separation at the lee side of the dunes is determined for a symmetric barchan dune in three dimensions, and for the height…
In this paper we derive and analyse mean-field models for the dynamics of groups of individuals undergoing a random walk. The random motion of individuals is only influenced by the perceived densities of the different groups present as well…
We observed time evolution of dune fields in a water tank experiment and simulated it by using a simple model without taking complex fluid dynamics into account. The initial sand bed changed its form into transverse ripples, that is, dunes…
Many complex aspects are involved in the morphodynamics of crescent-shaped dunes, known as barchans. One of them concerns the trajectories of individual grains over the dune, and how they affect its shape. In the case of subaqueous…
Sand dunes are ubiquitous in nature, and are found in abundance on Earth and other planetary environments. One of the most common types are crescent-shaped dunes known as barchans, whose mid-line could be assumed to behave as 2D dunes. In…