Energy Conversion最新文献_第2页

Analysis of Two-Phase Air/Water Bubbly Flow Experiment 气/水两相气泡流动实验分析

Energy Conversion Pub Date : 2002-01-01 DOI: 10.1115/IMECE2002-39689

D. Todd, Y. Hassan, J. Ortíz-Villafuerte

引用次数: 0

Mixing Field Analysis of a Gas Turbine Burner 某燃气轮机燃烧器混合场分析

Energy Conversion Pub Date : 2002-01-01 DOI: 10.1115/IMECE2002-39317

P. Flohr, Patrick Schmitt, C. Paschereit

{"title":"Mixing Field Analysis of a Gas Turbine Burner","authors":"P. Flohr, Patrick Schmitt, C. Paschereit","doi":"10.1115/IMECE2002-39317","DOIUrl":"https://doi.org/10.1115/IMECE2002-39317","url":null,"abstract":"An analytical and numerical study has been carried out with the view on the understanding of the physical mechanisms of the mixing process in a gas turbine burner. To this end, three methods at various levels of approximation have been used: At the simplest level an analytical model of the burner flow and the mixing process has been developed. It is demonstrated how this approach can be used to understand basic issues of the fuel-air mixing and how it can be applied as a design tool which guides the optimisation of a fuel injector device. At an intermediate level of approximation, steady-state CFD simulations, based on the k–e- and RSM-turbulence models are used to describe the mixing process. All steady simulations fail to either predict the recirculation zone or the turbulence level correctly, and can therefore not be expected to capture the mixing correctly. At the most involved level of modelling time-accurate CFD based on unsteady RSM and LES-turbulence models are performed. The simulations show good agreement with experiments (and in the case of LES excellent agreement) for both, velocity and turbulence fields. Mixing predictions close to the fuel injectors suffer from a simplification used in the numerical setup, but the mixing field is predicted very well towards the exit of the burner. The contribution of the asymmetric coherent flow structure (which is associated with the internal recirculation zone) to the mixing process is quantified through a triple decomposition technique.Copyright © 2002 by ASME","PeriodicalId":100466,"journal":{"name":"Energy Conversion","volume":"54 1","pages":"45-53"},"PeriodicalIF":0.0,"publicationDate":"2002-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77033563","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: 13

A Physical Model for Predicting Annular Film Flow Droplet Entrainment in Heat Transfer Systems 预测传热系统中环形膜流液滴夹带的物理模型

Energy Conversion Pub Date : 2002-01-01 DOI: 10.1115/IMECE2002-39279

M. J. Holowach, L. Hochreiter, F. Cheung

引用次数: 0

Numerical Simulation of Natural Gas Combustion Process Using a One-Step and a Two-Step Reaction 天然气燃烧过程一步和两步反应的数值模拟

Energy Conversion Pub Date : 2002-01-01 DOI: 10.1115/IMECE2002-39312

A. Nieckele, M. Naccache, Marcos S. P. Gomes, J. Carneiro, A. Isnard, R. Serfaty

引用次数: 4

The ampere-hour efficiency of photovoltaic solar generators 光伏太阳能发电机的安培小时效率

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90025-1

Donald G.S. Chuah

引用次数: 1

On the internal partition functions for the diatomic molecules N2, O2, NO and their ions—II. Maximum summation indices 关于双原子分子N2、O2、NO及其离子的内部配分函数——Ⅱ。最大求和指数

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90024-X

Jesse C. Denton

引用次数: 0

Electric effects in Window-Frame MHD generators with non-uniform velocity and conductivity in the transverse plane 具有非均匀速度和横向电导率的Window-Frame MHD发电机中的电效应

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90012-3

S.E. Shamma , M. Martinez-Sanchez, J.F. Louis

引用次数: 4

An incremental model for conversion of solar energy in agricultural systems 农业系统中太阳能转换的增量模型

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90011-1

M. Sanai

{"title":"An incremental model for conversion of solar energy in agricultural systems","authors":"M. Sanai","doi":"10.1016/0013-7480(79)90011-1","DOIUrl":"10.1016/0013-7480(79)90011-1","url":null,"abstract":"<div><p>Photosynthetic conversion of solar energy in agriculture leads to biomass storage of the intermittent solar irradiation. To explain and anticipate the data obtainable from prevailing soil-water-plant systems, an incremental model is devised in which various sectors present in the system are viewed as a series of discrete ‘compartments’ between which material and energy flow. Each compartment is to represent one of the main parameters encountered and their relations are assumed to be characterized by constant-coefficient linear differential equations. Presently, various coefficients that appear in the governing equations of a computerized version of this model are determined for alfalfa cultivation. The results indicate the balance and inter-relation of all the elements involved, and lead to the prediction of biomass energy yield per unit farm area, efficiency of photosynthetic conversion, and the cycling of the main nutrients. Furthermore, the changes that occur in the ecosystem parameters as a result of various operational schemes are predicted and it is shown that long-term soil pollution may occur as a consequence of soil contamination with excessive amounts of nutrients. One may thus regard the proposed model as a mathematical tool for determining the energy conversion capability of various agricultural systems, and obtain from it valuable guidance as to the choice of optimum farm management and type of crops suitable for any defined and specific purpose.</p></div>","PeriodicalId":100466,"journal":{"name":"Energy Conversion","volume":"19 1","pages":"Pages 9-13"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0013-7480(79)90011-1","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"106392465","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

Effect of diffusion on electron density across the nonequilibrium MHD channel 扩散对非平衡MHD通道电子密度的影响

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90010-X

M.S. Sodha, B.K. Gupta, R.P. Sharma

{"title":"Effect of diffusion on electron density across the nonequilibrium MHD channel","authors":"M.S. Sodha, B.K. Gupta, R.P. Sharma","doi":"10.1016/0013-7480(79)90010-X","DOIUrl":"10.1016/0013-7480(79)90010-X","url":null,"abstract":"<div><p>This paper presents an investigation of the effect of thermal diffusion of charge carriers on the electron density in a nonequilibrium MHD generator. The source of diffusion is the inhomogeneity in the background temperature and/or the nonuniform heating of electrons across the MHD channel cross section on account of the velocity boundary layer. The continuity equation of electrons has been solved in conjunction with the diffusion velocity equation to obtain the steady state electron density distribution in an MHD generator. As a result of diffusion, the electron density is found to increase with the distance from the channel axis, while the reverse is predicted from the assumption of local equilibrium. Further, it is seen that the increase in the values of Hall parameter, boundary layer thickness and the flow velocity enhances the effect of diffusion. Decrease in the wall temperature is also found to have a similar effect. The diffusion of the carriers is most prominent in the segmented geometry. It is concluded that overall electron density gets enhanced if recombination and diffusion times are of the same order.</p></div>","PeriodicalId":100466,"journal":{"name":"Energy Conversion","volume":"19 1","pages":"Pages 1-8"},"PeriodicalIF":0.0,"publicationDate":"1979-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/0013-7480(79)90010-X","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84799179","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: 6

Measurement of insolation using CdS photoresistor 使用CdS光敏电阻测量日晒

Energy Conversion Pub Date : 1979-01-01 DOI: 10.1016/0013-7480(79)90022-6

E. Klugmann , O.E. Onyeogu

引用次数: 10