In the current study, five different atomistic water models (AWMs) are implemented, In order to investigate the impact of AWMs treatment on the water velocity profile and density number. For this purpose, Molecular dynamics simulation (MDS) of Poiseuille flow in a nano-channel is conducted. Considered AWMs are SPC/E, TIP3P, TIP4P, TIP4PFQ and TIP5P. To assessment of the ability of each model in...

nanoscale science and technology has today mainly focused on the fabrication of nano devices. in this paper, we study the use of lithography process to build the desired nanostructures directly. nanolithography on polymethylmethacrylate (pmma) surface is carried out by using atomic force microscope (afm) equipped with silicon tip, in contact mode. the analysis of the results shows that the dept...

We present HydraTE, our own implementation of the smoothed-particle hydrodynamics technique for shallow water that uses the adaptive size of the smoothing kernel as a proxy for the local water depth. We derive the equations of motion for this approach from the Lagrangian before demonstrating that we can model the depth of water in a trough, implement vertical walls, recover the correct accelera...

[1] The exchange of water between a stream and its hyporheic zone (defined as the sediment beneath and immediately adjacent to a stream) underpins many ecological and hydrological functions in turbulent streams. Hyporheic exchange can be parameterized in terms of an effective diffusion coefficient Deff and considerable effort has gone into developing process-based models and empirical correlati...

The average velocity of water flow has been simultaneously measured with fluorescent and speckle imaging methods. The measured velocities with two methods are in good agreement with each other and it confirms that the speckle imaging method can be used as a confident method to measure the velocity of water flow in a dry leaf. Also the velocity of water flow through thick and thin xylems of a le...

Cnoidal wave theory is appropriate to periodic waves progressing in water whose depth is less than about one-tenth the wavelength. The leading results of existing theories are modified and given in a more practical form, and the graphs necessary to their use by engineers are presented. As well aa results for the wave celerity and shape, expressions and graphs for the water particle velocity and...

Different construction materials with different roughness used to make circular weirs highly affect surface roughness and, in turn, flow hydraulics passing over these structures.  In the present research, numerous experiments under different hydraulic conditions were performed on a physical model to study the effects of roughness on flow hydraulics over a circular weir. The flow hydraulics incl...

The vortex formation with the free surface variation in the shear layer of open channel flows is investigated by means of the plane-2D shallow water equations. The invisid instability analysis of the tanhtype velocity profile is firstly shown in order to make sure the applicability of the equations for the vortex formation in a free boundary layer. Then, the numerical simulation is made for the...

pipe drain installation depth is one of the most important design parameters, which has a key role in the drained water volume and quality. in this research, the effect of pipe drain installation depth was investigated by using a physical laboratory model. drains were installed at 0.25, 0.5 and 0.85 m deep in a cubical box with dimensions of 1*0.5*1 meter filled with a sandy loam soil. nitrate,...