scholarly journals ESTIMATION OF THE SIZE OF STAGNATION ZONES ON THE TERRITORY OF THE PROPANE-BUTANE TANK FARM AIMED AT INCREASING THE SAFETY OF THE FACILITY

2019 ◽  
Vol 16 (32) ◽  
pp. 656-667
Author(s):  
Mikhail V. OMELCHUK ◽  
Yuliya S. KOROTKOVA ◽  
Elizaveta A. VORONTSOVA

The safety of the territory is directly dependent upon the propane-butane storage and use technology. The paper reveals the efficiency of FlowVision software-based computational fluid dynamics technology (CFD) in modeling the stagnation zones and the behavior of fuel-air mixture (FAM) cloud within the territory of storage facilities. Propane-butane storage tank farm storage was selected as the object of research. CAD SolidWorks was used in the design of his three-dimensional model. Methods using "dispersed heavy gas models" have been developed. It is based on the numerical solution of three-dimensional fluid and gas dynamics equations, including the laws of conservation of mass, momentum (the Navier-Stokes equation) and constitutive equation. Recommendations on changes to be implemented during the design stage of tank farms with propane-butane mixture have been developed in order to increase facility safety in case of equipment depressurization. It is known that buildings, located on the territory, impair the airflow, resulting in the presence of large stagnant zones. It has been established that as a result of the movement of air flow through the territory of the tank farm, the maximum areas of stagnation zones are observed with the north wind and the minimum – with the southeast wind. Using the three-dimensional modeling techniques and finite volumes the stagnation zones in the tank farm were computed for different wind directions and measurement heights, enabling a comprehensive assessment of the situation at the facility in question and development of series of safety-increasing measures.

2014 ◽  
Vol 644-650 ◽  
pp. 2674-2677
Author(s):  
Kun Wang ◽  
Ke Yan Xiao

In order to study the evolution and metallogenic regularity of MVT lead-zinc deposits in western portion of Hunan province (China), two sets of three-dimensional model are established by Minexplorer software: 3D model in typical deposit and 3Dmodel on regional scale. On the basis of synthetic analyses of two sets of models, the further prospecting should be focused on the north part of ore-bearing layer along the Huayuan-Zhangjiajie fault belt. It is effective to observe occurrence and distribution characteristics from the 3D geological model, and to provide the basis for further exploration prospecting of the concealed deposits.


2011 ◽  
Vol 317-319 ◽  
pp. 789-793
Author(s):  
Xiao Feng Shang ◽  
Liang Tong ◽  
Zhi Jian Wang

The three-Dimensional model of 40BZ6-15 centrifugal pump is built by the Solidworks software. This paper employs three-D Navier-Stokes equation and standard equation, and uses MRF and STMPLE algorithm to simulate the internal flowing of the 40BZ6 centrifugal pump. The velocity field and pressure field are gained. Through a further analysis, the rule of the internal flow of the centrifugal pump is unveiled, and then the simulative results are compared with the experimental ones, which can provide the base for the further improvement of the centrifugal pump.


2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Alireza Jorkesh ◽  
Amir Hossein Ghaffari ◽  
Amir Abolfazleh Suratgar ◽  
Mahmoud Dehghan Afify

Abstract Till now, various models of the motion of nanobots have been submitted; the pioneer models, in spite of being exact in mathematics, had their own kind of problems. The most recent challenge is to describe a model whose attitude can be practical so that these motions can be estimated. Considering the massive uses of nanobots, the kinds of motions and velocities of these very small robots need to be studied in a more accurate way. In this essay, we tried to develop a three-dimensional model. The three dimensional model is based on 7 spheres and 6 arms and describes a kind of movement requiring 2 spheres at each arm. The velocity of each kind has also been evaluated. Furthermore, two kinds of three-dimensional movements have been issued and compared as well. That will result in the simplicity of the equations. By applying Oseen’s approximation in the Stokes’ equation, the velocity in various media has been calculated and modulated.


2002 ◽  
Vol 35 ◽  
pp. 538-544 ◽  
Author(s):  
Johannes Freitag ◽  
Uwe Dobrindt ◽  
Josef Kipfstuhl

AbstractIn this study a powerful tool to investigate the permeabilities and effective diffusion coefficients of polar firn is presented using a combination of an experimental method for three-dimensional pore-structure reconstruction and two models to simulate advective and diffusive transports of gases through the pore space. the reconstruction follows a semi-automated digital analysis of serial surface sections. the simulations are based on a three-dimensional lattice Boltzmann formulation. They separately solve the Navier–Stokes equation and the diffusive transport equations. In a first application, effective diffusion coefficients and permeabilities are calculated from firn samples of a core drilled during the North Greenland Traverse 1993–95. the estimated relationships of diffusivity and permeability to the open porosity are expressed by power-law functions with exponents 2.1 and 3.4, respectively.


2021 ◽  
Vol 20 (7) ◽  
pp. 48-61
Author(s):  
Pavel V. Chistyakov ◽  
Ekaterina N. Bocharova ◽  
Ksenia A. Kolobova

This article provides a detailed account of the process of scanning, post-processing and further manipulation of three-dimensional models obtained with structured light scanners. Purpose. The purpose of the study is determined by the need for national archaeologists to learn the methods of three-dimensional modeling for the implementation of scientific research corresponding to international standards. Unfortunately, this direction in national archaeology began to develop in a relatively recent time and there is a lag in the application of three-dimensional modeling of national archaeology compared to the world level. Results. Any archaeological, experimental or ethnographic artifact can be used for three-dimensional scanning. To perform post-processing of three-dimensional models it is necessary to carry out primary scanning of an artifact by one of the existing algorithms. The algorithm for creating models, their positioning, simplification, saving in various formats and export is described. The main sequence of 3D models post-processing includes: processing of groups of scanned projections (their cleaning and alignment), creation of artifact model and processing/rectification of the resulting model using special software. Conclusion. As a result of correct implementation of the algorithm, the researcher receives a scaled model completely corresponding to the original artifact. Obtaining a scalable, texture-free three-dimensional model of the artifact, which fully corresponds to the original and exceeds a photograph in the quality of detail transfer, allows a scientist to conduct precise metric measurements and any procedures of non-invasive manipulation of the models. The ability to access a database of three-dimensional models of archaeological collections greatly simplifies the work of archaeologists, especially in situations when country borders are closed.


2011 ◽  
Vol 685 ◽  
pp. 461-494 ◽  
Author(s):  
Alain Merlen ◽  
Christophe Frankiewicz

AbstractThe flow around a cylinder rolling or sliding on a wall was investigated analytically and numerically for small Reynolds numbers, where the flow is known to be two-dimensional and steady. Both prograde and retrograde rotation were analytically solved, in the Stokes regime, giving the values of forces and torque and a complete description of the flow. However, solving Navier–Stokes equation, a rotation of the cylinder near the wall necessarily induces a cavitation bubble in the nip if the fluid is a liquid, or compressible effects, if it is a gas. Therefore, an infinite lift force is generated, disconnecting the cylinder from the wall. The flow inside this interstice was then solved under the lubrication assumptions and fully described for a completely flooded interstice. Numerical results extend the analysis to higher Reynolds number. Finally, the effect of the upstream pressure on the onset of cavitation is studied, giving the initial location of the phenomenon and the relation between the upstream pressure and the flow rate in the interstice. It is shown that the flow in the interstice must become three-dimensional when cavitation takes place.


2005 ◽  
Vol 19 (28n29) ◽  
pp. 1539-1542
Author(s):  
ZHANG LI ◽  
DENGBIN TANG ◽  
LINLIN GUO

The generation and the development of turbulent coherent structures in channel flows are investigated by using numerical simulation of Navier-Stokes equation and the theoretic model of turbulent coherent structures built up by the flow stability theories. The three-dimensional coupling compact difference scheme with high accuracy and resolution developed can be applied to the calculative region including points near the boundary. The results computed show nonlinear evolution process and characteristics of Reynolds stress, stream-wise vortices and span-wise vorticities, especially the nonlinear interactions between different coherent structures.


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