Experience with fluid-flow simulation suggests that, in some instances, under-resolved direct numerical simulation (DNS), without a residual-stress model per se but with artificial damping of small scales to account for energy lost in the cascade from resolved to unresolved scales, may be as reliable as simulations based on more complex models of turbulence. One efficient and versatile manner t...

This paper deals with pump as turbine (PAT) as a feasible solution to the energy problems in rural and hilly areas. PAT provides an economical alternative to actual turbines especially for pico and microhydropower generation. PAT is essentially a pump operating in turbine mode by changing direction of flow and hence the direction of rotation of the impeller. In the forthcoming discussion, an in...

Wave breaking is important for understanding of both sea wave dynamics and microwave scattering/emission of the ocean. Experimental studies of breaking waves are mostly related to tank measurements and to a lesser extent to field observations [1, 2]. Theoretical results regarding wave breaking are mostly obtained by numerical simulation [3]. Comparison of those with tank experiments leads to th...

In this paper a mathematical simulation of a simplified internal combustion engine is presented. To contribute engine kinematics and its geometry, simple relations are derived for constrained motions. The equation of motion for the piston forms a singular boundary value problem. The uniqueness of the solution was studied in the Banach space. For solving governing equations an iterative numerica...

This article deals with the numerical approximation of Markovian backward stochastic differential equations (BSDEs) with generators of quadratic growth with respect to z and bounded terminal conditions. We first study a slight modification of the classical dynamic programming equation arising from the time-discretization of BSDEs. By using a linearization argument and BMO martingales tools, we ...

Robotics is, among other things, the study of complex hardware-software systems. In a complex system, many components interact, giving rise to emergent behaviors that can be hard to explain, anticipate, or design. Rather than just evaluating the system as a whole, we would often prefer first to evaluate components of the system individually. For instance, robotic mechanism design incorporates s...

We present a simple mathematical model and numerical simulations of the hexagonal pattern formation of a honeycomb using the immersed boundary method. In our model, we assume that the cells have a circular shape at their birth and there is force acting upon the entire circumference of the cell. The net force from the individual cells is a key factor in their transformation from a circular shape...

local scouring around bridge piers is a natural phenomenon caused by the erosive process of flowing stream on alluvial beds. the 3d flow field around bridge piers interacting with the bed materials increases complexity of local scour process. the local scour depth develops in accelerated flows and if it is not predicted correctly, the bottom level of local scour hole will exceed the original le...