We propose a high order explicit finite difference method for fractional advection diffusion equations. These equations can be obtained from the standard advection diffusion equations by replacing the second order spatial derivative by a fractional operator of order α with 1 < α ≤ 2. This operator is defined by a combination of the left and right Riemann–Liouville fractional derivatives. We stu...

The Tibetan Plateau (TP), known as the third pole of the Earth, has snow cover with intraseasonal to decadal variability that affects weather and climate both inside and outside the TP. However, the factors that generate the TP snow cover (TPSC) anomalies at the intraseasonal time-scale are unclear. This report reveals the influence of the Madden‒Julian oscillation (MJO), which is the most domi...

We propose a general approach for the numerical approximation of optimal control problems governed by a linear advection–diffusion equation, based on a stabilization method applied to the Lagrangian functional, rather than stabilizing the state and adjoint equations separately. This approach yields a coherently stabilized control problem. Besides, it allows a straightforward a posteriori error ...

Automatic identification and tracking of mesoscale eddies are crucial in large oceanic observational numerical model data. This work proposes a fully automated method that identifies tracks from single Lagrangian advection, all eddies, without prior knowledge their lifespans. The eddies' detection use hybrid based on geometrical properties the evolving velocity along trajectories grid density-b...

MacCormack's method is an explicit, second order nite diierence scheme that is widely used in the solution of hyperbolic problems. Here, we consider MacCormack's method applied to the linear advection equation with nonlinear source term. Various features of the method are analysed. First, we show that the conventional implementation is not stable for Courant numbers close to one unless a small ...

We devise a numerical method for passive advection of a surface, such as the interface between two incompressible fluids, across a computational mesh. The method is called isoAdvector, and is developed for general meshes consisting of arbitrary polyhedral cells. The algorithm is based on the volume of fluid (VOF) idea of calculating the volume of one of the fluids transported across the mesh fa...

a subsurface drainage network mainly carries unsteady flow and data are not usually available for model parameters calibration in such networks. in the present research, the finite volume method using the time splitting scheme was employed to develop a computer code for solving the one dimensional unsteady flow equations. using corrugated sub drainage pipes, an experimental prototype setup was ...

Both the chaotic mixers (Fig.1) adopt a two-layer overlapping channels structure, which is very efficient for fluid manipulations such as stretching and folding, splitting and recombination. Even at extremely low Re (~10), chaotic advection can be generated. Both particle tracing simulation (Fig. 2) and experimental results (Fig.3) show that as the fluids are driven through the mixer, striation...

Abstract. With the depletion of oil reserves and increase in oil price, the enhanced oil recovery methods such as polymer flooding to increase oil production from waterflooded fields are becoming more attractive. Effective design of these processes is challenging because the polymer chemistry has a strong effect on reaction and fluid rheology, which in turn has s strong effect on fluid transpor...

Immigration, emigration, migration, and redistribution describe processes that involve movement of individuals. These movements are an essential part of contemporary ecological models, and understanding how movement is affected by biotic and abiotic factors is important for effectively modeling ecological processes that depend on movement. We asked how phenotypic heterogeneity (body size) and e...