Numerical Simulations in Engineering and Science最新文献

Benchmarks for Non-Ideal Magnetohydrodynamics 非理想磁流体力学基准

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.75713

S. Vasily, Zhmailo Vadim, Yanilkin Yury

引用次数: 0

Study of the Numerical Diffusion in Computational Calculations 数值扩散在计算中的研究

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.75660

D. Karadimou, N. Markatos

{"title":"Study of the Numerical Diffusion in Computational Calculations","authors":"D. Karadimou, N. Markatos","doi":"10.5772/INTECHOPEN.75660","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.75660","url":null,"abstract":"The numerical simulation of fluid flow and heat/mass-transfer phenomena requires the numerical solution of the Navier-Stokes and energy-conservation equations coupled with the continuity equation. Numerical or false diffusion is the phenomenon of inserting errors in the calculations that compromise the accuracy of the computational solution. The Taylor series analysis that reveals the truncation/discretization errors of the differen- tial equations terms should not be termed as false diffusion. Numerical diffusion appears in multi-dimensional flows when the differencing scheme fails to account for the true direction of the flow. Numerical errors associated with false diffusion are investigated via two- and three-dimensional problems. A numerical scheme must satisfy necessary criteria for the successful solution of the convection-diffusion formulations. The common practice of approximating the diffusion terms via the central-difference approximation is satisfactory. Attention is directed to the convection terms since these approximations induce false diffusion. The equations of all the conservation equations in this study are discretized by the finite volume method.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"76 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121653029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Numerical Modeling of Chemical Compounds’ Fate and Kinetics in Living Organisms: An Inverse Numerical Method for Rate Estimation from Concentration 化合物在生物体中的命运和动力学的数值模拟:一种从浓度估计速率的反数值方法

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.76611

K. Dalma, Kovacs Melinda Haydee

{"title":"Numerical Modeling of Chemical Compounds’ Fate and Kinetics in Living Organisms: An Inverse Numerical Method for Rate Estimation from Concentration","authors":"K. Dalma, Kovacs Melinda Haydee","doi":"10.5772/INTECHOPEN.76611","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.76611","url":null,"abstract":"Emerging chemical compounds are ubiquitous in all environmental compartments and may pose a risk to biota ecosystems. The quantification and prediction of environmental partitioning of these chemicals in various environmental compartment systems (water, sediments, soil, air, biota) is an important step in the comprehensive assessment of their sources, fates, and not finally of their uptake potential by various living organisms of ecosystems. Any numerical solution that has as a final goal “prediction” requires a large number of experimental data. In case of environmental studies of chemical compounds, monitoring most studies is costly, time-consuming, and requires both qualified personnel and high- precision equipment. Finding a suitable numerical model that could predict the fate of chemicals could be extremely useful, facilitating those environmental scientists, users, managers, authorities, and corresponding decision-makers for a more conscious use of these substances, thus protecting the environment and biota. Considering the mentioned disadvantages regarding chemical compounds’ monitoring, the aim of this research is to find numerical solutions that enable the prediction of such chemical compounds’ fate under different environmental compartments and the uptake potential by living organisms as plants. The concept of the inverse numerical method was used in order to find chemical compounds’ rate of accumulation in various environ- mental matrixes and potential uptake by living organisms, all starting from the chemical compounds’ concentrations.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129108050","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Numerical Simulation of Electronic Systems Based on Circuit- Block Partitioning Strategies 基于电路块划分策略的电子系统数值模拟

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.75490

J. Oliveira

引用次数: 0

Analytical and Mathematical Analysis of the Vibration of Structural Systems Considering Geometric Stiffness and Viscoelasticity 分析和数学分析结构的振动系统的考虑几何刚度和粘弹性

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.75615

A. Wahrhaftig, R. Brasil, Lázaro S. M. S. C. Nascimento

{"title":"Analytical and Mathematical Analysis of the Vibration of Structural Systems Considering Geometric Stiffness and Viscoelasticity","authors":"A. Wahrhaftig, R. Brasil, Lázaro S. M. S. C. Nascimento","doi":"10.5772/INTECHOPEN.75615","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.75615","url":null,"abstract":"For a complete analysis of vibration, the stiffness of a structure must have two character- istics: one corresponding to conventional stiffness and the other to the geometric stiffness. Thus, the total stiffness takes form where the model to be used to represent any behavior of the material is introduced to the first part via the modulus of elasticity. The second is the geometric stiffness, through which it is possible to linearize a geometric nonlinear prob- lem. To consider both aspects, a mathematical model based on the Rayleigh method has been elaborated. Two systems were numerically studied. First, the occurrence of reso- nance in the vibration of a prestressed reinforced concrete beam has been investigated. The results indicated resonant and non-resonant schemes between the natural frequency of the beam and the frequency of the engine. To the second system, the first natural frequency of a slender, 40-m-high concrete mobile phone mast, was calculated, and an evaluation of the structural collapse was performed. To the both systems, the cross section of reinforced concrete was treated by the theory for the homogenized section in order to consider the presence of the steel, and the viscoelasticity of the concrete was taken into account through a three-parameter rheological model.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"32 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125387485","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Numerical Simulation of Nanoparticles with Variable Viscosity over a Stretching Sheet 变粘度纳米颗粒在拉伸薄片上的数值模拟

Numerical Simulations in Engineering and Science Pub Date : 2018-07-11 DOI: 10.5772/INTECHOPEN.71224

N. Akbar, D. Tripathi, Zafar Hayat Khan

{"title":"Numerical Simulation of Nanoparticles with Variable Viscosity over a Stretching Sheet","authors":"N. Akbar, D. Tripathi, Zafar Hayat Khan","doi":"10.5772/INTECHOPEN.71224","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.71224","url":null,"abstract":"The effects of different typesof base fluidsoncarbon nanotube(CNT) nanofluids flow over a circular stretching sheet are numerically analyzed. The nonlinear variation of radial velocity in radial direction is assumed at surface of stretching sheet. The temperature dependent fluid viscosity is taken into consideration. Two different types of flows (assisting flow and opposing flow) are discussed under the buoyant force effects. Single walled CNT and multi walled CNT are considered as nanoparticles for better thermal conductivity of the nanofluids. A set of similarity transformations to convert the partial differential equations into ordinarydifferentialequations is hired.The non-linearODEsare numerically solved by employing fourth order Runge-Kutta method. Discussions of numerical simulations for flow characteristics have been made appropriately. A compara-tive study for various type of base fluids like kerosene, engine oil and ethylene glycol is also presented. From the predicted simulation, it is observed that the variation in Nusselt number is maximum for engine oil and minimum for kerosene oil however, the variation in skin friction coefficient is largest for kerosene oil and least for engine oil. Furthermore, numerical results are also validated with achieving a goodcorrelation with existing results.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"46 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-07-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124005013","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

Twin-Grating Fiber Optic Sensors Applied on Wavelength- Division Multiplexing and Its Numerical Resolution 双光栅光纤传感器在波分复用中的应用及其数值分辨率

Numerical Simulations in Engineering and Science Pub Date : 2018-04-11 DOI: 10.5772/INTECHOPEN.75586

José Trinidad Guillen Bonilla, Héctor Guillen Bonilla, A. Zamora, G. A. Gómez, Nancy Elizabeth Franco Rodríguez, Alex Guillen Bonilla, Juan R. Gómez

{"title":"Twin-Grating Fiber Optic Sensors Applied on Wavelength- Division Multiplexing and Its Numerical Resolution","authors":"José Trinidad Guillen Bonilla, Héctor Guillen Bonilla, A. Zamora, G. A. Gómez, Nancy Elizabeth Franco Rodríguez, Alex Guillen Bonilla, Juan R. Gómez","doi":"10.5772/INTECHOPEN.75586","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.75586","url":null,"abstract":"In this work, the twin-grating fiber optic sensor has been applied on wavelength-division multiplexing. A quasi-distributed sensor formed by three local twin-grating sensors, is numerically simulated. The wavelength channels were 1531.5, 1535.5, and 1539.5 nm. The numerical simulation shows the resolution vs. signal-to-noise rate. Three local twin-grating sensors have approximately the same resolution because all local sensors have the same cavity length and the wavelength channels are very close. All local sensors have two numerical resolutions because the Fourier domain phase analysis algorithm makes two evaluations of the Bragg wavelength shift. The transition between both resolutions can be calculated with the parameters: cavity length, Bragg wavelength channel, refrac- tion index, and enveloped resolution. This transition depends on the noise system, demodulation algorithm, instrumentation, and local sensor properties. A very important point is, a theoretical analysis will permit to know the exact resolution for each local twin-grating sensor.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"37 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-04-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121825540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

Numerical Study of Turbulent Flows and Heat Transfer in Coupled Industrial-Scale Tundish of a Continuous Casting Material in Steel Production 钢铁生产中连铸材料工业规模耦合中间包湍流流动与传热数值研究

Numerical Simulations in Engineering and Science Pub Date : 2018-04-09 DOI: 10.5772/INTECHOPEN.75935

J. A. Castro, B. A. Pereira, Roan Sampaio deSouza, E. M. Oliveira, I. Ferreira

引用次数: 2

Ultrashort Pulse Generation in Ce:LiCAF Ultraviolet Laser Ce:LiCAF紫外激光器中超短脉冲的产生

Numerical Simulations in Engineering and Science Pub Date : 2018-03-21 DOI: 10.5772/INTECHOPEN.73501

M. Cadatal-Raduban, M. Pham, Luong Viet Mui, N. Hung, N. Sarukura

引用次数: 1

Numerical Simulations of a High-Resolution RANS-FVDM Scheme for the Design of a Gas Turbine Centrifugal Compressor 燃气轮机离心压缩机高分辨率ransr - fvdm设计方案的数值模拟

Numerical Simulations in Engineering and Science Pub Date : 2018-02-06 DOI: 10.5772/INTECHOPEN.72098

CH. V. K. N. S. N. Moorthy, V. Srinivas

{"title":"Numerical Simulations of a High-Resolution RANS-FVDM Scheme for the Design of a Gas Turbine Centrifugal Compressor","authors":"CH. V. K. N. S. N. Moorthy, V. Srinivas","doi":"10.5772/INTECHOPEN.72098","DOIUrl":"https://doi.org/10.5772/INTECHOPEN.72098","url":null,"abstract":"The aero-thermodynamic design and performance of a compressor need to conquer many vital challenges like it is a gas-driven turbo-machinery component, involvement of extensive iterative process for the convergence of the design, enormous design complexity due to three-dimensional flow phenomena, and multiflow physics embedded within a dynamic state-of-the-art. In this chapter, a strong attempt is made to address the above-cited techni- cal issues to achieve an optimized design and performance of a centrifugal compressor with backward swept blade profile producing total pressure ratio of 5.4 with an ingested mass flow rate of 5.73 kg/s. A mean-line design methodology was implemented to configure sizing of the compressor. An optimum grid size was well validated by carrying out compu- tational analysis with three different mesh sizes within the same framework. Finally, a detailed three-dimensional numerical simulation was performed using Reynolds-averaged Navier-Stokes equations based on finite volume discretization method (RANS-FVDM) scheme. Consequently, the polytropic efficiency, total-to-total efficiency, stagnation pressure ratio at a fixed rotational speed, and the overall design and aero-thermodynamic performance of the centrifugal compressor are validated.","PeriodicalId":103650,"journal":{"name":"Numerical Simulations in Engineering and Science","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2018-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130993591","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0