NUMERICAL SIMULATION FOR RIVER BED TOPOGRAPHY USING FREE SOFTWARE AND FACTOR ANALYSIS BASED ON THE LINEAR INSTABILITY INDEX

The work is devoted to the numerical study of indoor microclimate. Accurately predicting the distributed microclimate inside the residential space equipped with a microclimate control system called the «smart house» allows to save thermal energy significantly. Mathematical modeling was carried out by means of the Navier-Stokes equation, the energy equation, the continuity equation. The system of equations used was closed using the k-w-sst turbulence model. The resulting numerical solution was performed in the Code_Saturn, which has a free license. The Salome free software package was used to build a grid. In this context, a second–order scheme (SOLU) was used to resolve the velocity field, a MULTIGRID scheme was used for the pressure field, automatic settings were used for the kinetic energy of turbulence and her dissipation and for the temperature field, the maximum number of iterations for each cycle was equal to 10000, the Solver Precision accuracy was 10-8. The SIMPLEC algorithm is used to obtain a connected solution of the momentum balance and continuity equations. The paper provides an example of numerical solution verification, which is showed the relative temperature deviation from the values obtained by other authors was no more than 0.8-1.2%. Numerical simulation of the air velocity field in the residential space showed values from 0.12 to 0.15 m/s. Based on the results of the obtained solution, an analysis of the saving of thermal energy was carried out when regulating the supply of heat.

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Short communication: Multiscalar drag decomposition in fluvial systems using a transform-roughness correlation (TRC) approach

10.5194/esurf-2020-51 ◽

2020 ◽

Author(s):

David L. Adams ◽

Andrea Zampiron

Keyword(s):

Flow Resistance ◽

Total Flow ◽

Fluvial Systems ◽

Bed Topography ◽

Relative Contribution ◽

River Bed ◽

Roughness Elements ◽

Wide Range ◽

Novel Method ◽

Individual Grains

Abstract. In natural open-channel flows over complex surfaces, a wide range of superimposed roughness elements may contribute to flow resistance. Gravel-bed rivers present a particularly interesting example of this kind of multiscalar flow resistance problem, as both individual grains and bedforms can potentially be important roughness elements. In this paper, we propose a novel method of estimating the relative contribution of different physical scales of river bed topography to the total drag, using a transform-roughness correlation (TRC) approach. The technique, which requires only a single longitudinal profile, consists of (1) a wavelet transform which decomposes the surface into roughness elements occurring at different wavelengths, and (2) a `roughness correlation' that estimates the drag associated with each wavelength based on its geometry alone, expressed as ks. We apply the TRC approach to original and published laboratory experiments and show that the multiscalar drag decomposition yields estimates of grain- and form-drag that are consistent with estimates in channels with similar morphologies. Also, we demonstrate that the roughness correlation may be used to estimate total flow resistance via a conventional equation, suggesting that it could replace representative roughness values such as median grain size or the standard deviation of elevations. An improved understanding of how various scales contribute to total flow resistance may lead to advances in hydraulics as well as channel morphodynamics.

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Geographical Background of the Bhabar-Tarai Belt of Lower Assam District, India

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.e4983.018520 ◽

2020 ◽

Vol 8 (5) ◽

pp. 1299-1304

Keyword(s):

Animal Species ◽

Forest Cover ◽

Secondary Data ◽

Point Of View ◽

Bed Topography ◽

Rich Domain ◽

Diverse Species ◽

River Bed ◽

Shelter Belt ◽

Physical Features

From geo-ecological point of view, the BhabarTarai belt bears immense significance as it considers as shelter belt for diverse species. It may be mentioned as a hub of interaction among all biota that holds life to sustain. Being a rich domain in respect of plant and animal species, the belt is composed by pebbles, sand, and silt with thick forest cover and ranges from dry disappearance river bed topography to wet, marshy land one. With an area of 3994.25 sq.km, Lower Assam district is also flourished by this notable structure of physiography out of which 89.24% are Tarai followed by 10.75% of Bhabar. Most of the area is covered by BTAD areas along withsignified Assam-Bhutan Boarder that support a great number of people with their associated livelihood compositions. For more details, there has made an attempt of analysis this important zone of physical features along with adopted form of belongingness of people to the area as well. The paper is prepared on the basis of both primary and secondary data and findings are represented with the help different digital cartographic techniques.

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Test Studyed of Yangjiawan Grand Bridge in the Project of Lanyu Railway by Movable Bed Model

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.204-208.2070 ◽

2012 ◽

Vol 204-208 ◽

pp. 2070-2073

Author(s):

Wen She He ◽

Long Yuan ◽

Shuang Mei Chang ◽

Jing Jing Feng ◽

Liang Ming Wang

Keyword(s):

Flood Control ◽

Yellow River ◽

Flow Direction ◽

Bridge Site ◽

Design Data ◽

Lanzhou City ◽

Bed Topography ◽

River Bed ◽

Before And After ◽

Movable Bed

Yangjiawan grand bridge is located in Lanzhou section of the Yellow River. In order to study the change laws near the bridge site of flow direction, velocity distribution, water surface slope, backwater area, river bed topography change and the effect of flood control on Lanzhou city after the bridge-built when the river gets through the average discharge, 20-year discharge, and 100-year discharge before and after the bridge-built. Based on the similar principle of model, the river near the bridge site was simulated by the hydraulic model experiment of movable bed. The result of experiment showed that the design data adopted in bridge project of Yangjiawan grand bridge were reasonable and fulfilled the requirements of city flood control. It was also suggested to excavate and dredge river near the piers of 6# ~11# and strengthen embankment near the riverbank and protection of constructions after the bridge-built.

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