This paper investigates the entropy generation in a third-grade fluid flow with variable properties through a channel. Approximate solutions to the nonlinear boundary-value problem are obtained using Adomian decomposition method (ADM). Variation of important parameters on the fluid velocity, temperature distribution, entropy generation and irreversibility ratio are presented graphically and discussed.
{"title":"Second Law Analysis for Third-Grade Fluid with Variable Properties","authors":"S. Adesanya","doi":"10.1155/2014/452168","DOIUrl":"https://doi.org/10.1155/2014/452168","url":null,"abstract":"This paper investigates the entropy generation in a third-grade fluid flow with variable properties through a channel. Approximate solutions to the nonlinear boundary-value problem are obtained using Adomian decomposition method (ADM). Variation of important parameters on the fluid velocity, temperature distribution, entropy generation and irreversibility ratio are presented graphically and discussed.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"14 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2014-09-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81458369","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}
The present investigation deals with the propagation of waves in fiber-reinforced transversely isotropic thermoelastic solid half space with initial stresses under a layer of inviscid liquid. The secular equation for surface equation in compact form is derived after developing the mathematical model. The phase velocity and attenuation coefficients of plane waves are studied numerically for a particular model. Effects of initial stress and thickness of the layer on the phase velocity, attenuation coefficient, and specific loss of energy are predicted graphically in the certain model. A particular case of Rayleigh wave has been discussed and the dispersion curves of the phase velocity and attenuation coefficients have also been presented graphically. Some other particular cases are also deduced from the present investigation.
{"title":"Effect of Initial Stress on the Propagation Characteristics of Waves in Fiber-Reinforced Transversely Isotropic Thermoelastic Material under an Inviscid Liquid Layer","authors":"Rajesh Kumar, Sanjeev Ahuja, S. K. Garg","doi":"10.1155/2014/134276","DOIUrl":"https://doi.org/10.1155/2014/134276","url":null,"abstract":"The present investigation deals with the propagation of waves in fiber-reinforced transversely isotropic thermoelastic solid half space with initial stresses under a layer of inviscid liquid. The secular equation for surface equation in compact form is derived after developing the mathematical model. The phase velocity and attenuation coefficients of plane waves are studied numerically for a particular model. Effects of initial stress and thickness of the layer on the phase velocity, attenuation coefficient, and specific loss of energy are predicted graphically in the certain model. A particular case of Rayleigh wave has been discussed and the dispersion curves of the phase velocity and attenuation coefficients have also been presented graphically. Some other particular cases are also deduced from the present investigation.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"4 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2014-08-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77846500","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}
A numerical procedure for deriving the thermodynamic properties , , and of the vapor phase in the subcritical temperature range from the speed of sound is presented. The set of differential equations connecting these properties with the speed of sound is solved as the initial-value problem in domain . The initial values of and are specified along the isotherm with the highest temperature, at a several values of [0.1, 1.0]. The values of are generated by the reference equation of state, while the values of are derived from the speed of sound, by solving another set of differential equations in domain in the transcritical temperature range. This set of equations is solved as the initial-boundary-value problem. The initial values of and are specified along the isochore in the limit of the ideal gas, at several isotherms distributed according to the Chebyshev points of the second kind. The boundary values of are specified along the same isotherm and along another isotherm with a higher temperature, at several values of . The procedure is tested on Ar, N2, CH4, and CO2, with the mean AADs for , , and at 0.0003%, 0.0046%, and 0.0061%, respectively (0.0007%, 0.0130%, and 0.0189% along the saturation line).
{"title":"Thermodynamic Properties of Vapors from Speed of Sound","authors":"M. Bijedić, S. Begić","doi":"10.1155/2014/231296","DOIUrl":"https://doi.org/10.1155/2014/231296","url":null,"abstract":"A numerical procedure for deriving the thermodynamic properties , , and of the vapor phase in the subcritical temperature range from the speed of sound is presented. The set of differential equations connecting these properties with the speed of sound is solved as the initial-value problem in domain . The initial values of and are specified along the isotherm with the highest temperature, at a several values of [0.1, 1.0]. The values of are generated by the reference equation of state, while the values of are derived from the speed of sound, by solving another set of differential equations in domain in the transcritical temperature range. This set of equations is solved as the initial-boundary-value problem. The initial values of and are specified along the isochore in the limit of the ideal gas, at several isotherms distributed according to the Chebyshev points of the second kind. The boundary values of are specified along the same isotherm and along another isotherm with a higher temperature, at several values of . The procedure is tested on Ar, N2, CH4, and CO2, with the mean AADs for , , and at 0.0003%, 0.0046%, and 0.0061%, respectively (0.0007%, 0.0130%, and 0.0189% along the saturation line).","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"12 1","pages":"1-5"},"PeriodicalIF":0.0,"publicationDate":"2014-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80928972","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}
We have implemented a visualization tool for the demonstration of a nonideal Carnot engine, operating at finite time. The cycle time can be varied using a slide bar and the pressure-volume, temperature-entropy, power-time, and efficiency-time diagrams change interactively and are shown on one screen. We have evaluated the visualization tool among engineering students at university level during an introductory course on thermodynamics and we review and discuss the outcome of the evaluation.
{"title":"Pedagogical Visualization of a Nonideal Carnot Engine","authors":"J. Johansson","doi":"10.1155/2014/217187","DOIUrl":"https://doi.org/10.1155/2014/217187","url":null,"abstract":"We have implemented a visualization tool for the demonstration of a nonideal Carnot engine, operating at finite time. The cycle time can be varied using a slide bar and the pressure-volume, temperature-entropy, power-time, and efficiency-time diagrams change interactively and are shown on one screen. We have evaluated the visualization tool among engineering students at university level during an introductory course on thermodynamics and we review and discuss the outcome of the evaluation.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"3 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2014-07-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81826816","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}
The study on temperature dependent γ-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300 K–1250 K using different energies of γ-beam, namely, Am (0.0595 MeV), Cs (0.66 MeV), and Co (1.173 MeV and 1.332 MeV) on γ-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (μl) for the pellets of CaO and MgO as a function of temperature have been determined using γ-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300 K–1250 K has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported.
在自制的γ射线密度计上，利用不同能量的γ射线束Am (0.0595 MeV)、Cs (0.66 MeV)和Co (1.173 MeV和1.332 MeV)，对CaO和MgO在300 K - 1250 K温度范围内的γ射线衰减和热物理性质进行了研究。用不同能量的γ射线束测定了氧化钙和氧化镁球团的线性衰减系数μl随温度的变化。已经报道了密度的温度依赖系数。研究了CaO和MgO在300 K - 1250 K温度范围内的密度变化和线性热膨胀，并与文献结果进行了比较。线性衰减系数、密度和热膨胀与温度的关系用二次多项式表示。体积热膨胀系数已有报道。
{"title":"Studies on Thermophysical Properties of CaO and MgO by -Ray Attenuation","authors":"A. M. Rao, K. Narender","doi":"10.1155/2014/123478","DOIUrl":"https://doi.org/10.1155/2014/123478","url":null,"abstract":"The study on temperature dependent γ-ray attenuation and thermophysical properties of CaO and MgO has been carried out in the temperature range 300 K–1250 K using different energies of γ-beam, namely, Am (0.0595 MeV), Cs (0.66 MeV), and Co (1.173 MeV and 1.332 MeV) on γ-ray densitometer fabricated in our laboratory. The linear attenuation coefficients (μl) for the pellets of CaO and MgO as a function of temperature have been determined using γ-beam of different energies. The coefficients of temperature dependence of density have been reported. The variation of density and linear thermal expansion of CaO and MgO in the temperature range of 300 K–1250 K has been studied and compared with the results available in the literature. The temperature dependence of linear attenuation coefficients, density, and thermal expansion has been represented by second degree polynomial. Volume thermal expansion coefficients have been reported.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"4 1","pages":"1-8"},"PeriodicalIF":0.0,"publicationDate":"2014-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81926558","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}
This paper has applied thermodynamics principles to evaluate the reliability of 390 m3/hr natural gas processing plant. The thermodynamics equations were utilized in the evaluation, characterization, and numerical simulation of key process parameters in natural gas liquid extraction plant. The results obtained show the comparison of the coefficient of performance, compression ratio, isentropic work, actual work, electrical power requirements, cooling water consumption in intercoolers, compressor power output, compressor capacity, and isentropic, volumetric, and mechanical efficiency of the two-stage refrigeration unit with a flash gas economizer and these were compared with the designed specifications. The second law of thermodynamics was applied in analyzing the refrigeration unit and the result shows that exergetic losses or lost work due to irreversibility falls within operating limit that is less than 1.0%. Similarly, the performance of expansion turbine (expander) parameters was monitored and the results indicate a considerable decrease in turbine efficiencies as the inlet gas pressure increases resulting in an increased power output of the turbine leading to a higher liquefaction rate.
{"title":"Performance Evaluation of Refrigeration Units in Natural Gas Liquid Extraction Plant","authors":"A. A. Ujile, Dirina Amesi","doi":"10.1155/2014/863408","DOIUrl":"https://doi.org/10.1155/2014/863408","url":null,"abstract":"This paper has applied thermodynamics principles to evaluate the reliability of 390 m3/hr natural gas processing plant. The thermodynamics equations were utilized in the evaluation, characterization, and numerical simulation of key process parameters in natural gas liquid extraction plant. The results obtained show the comparison of the coefficient of performance, compression ratio, isentropic work, actual work, electrical power requirements, cooling water consumption in intercoolers, compressor power output, compressor capacity, and isentropic, volumetric, and mechanical efficiency of the two-stage refrigeration unit with a flash gas economizer and these were compared with the designed specifications. The second law of thermodynamics was applied in analyzing the refrigeration unit and the result shows that exergetic losses or lost work due to irreversibility falls within operating limit that is less than 1.0%. Similarly, the performance of expansion turbine (expander) parameters was monitored and the results indicate a considerable decrease in turbine efficiencies as the inlet gas pressure increases resulting in an increased power output of the turbine leading to a higher liquefaction rate.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"26 1","pages":"1-7"},"PeriodicalIF":0.0,"publicationDate":"2014-03-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"82867640","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}
Densities, , and ultrasonic speeds, of mixtures of 1-butanol or iso-butanol or t-butanol with equimolar mixture of (N,N-dimethylacetamide
1-丁醇、异丁醇或正丁醇与(N,N-二甲基乙酰胺等摩尔混合物的密度和超声波速度
{"title":"Acoustic and Volumetric Properties of Mixture of (N,N-Dimethylacetamide","authors":"M. Kondaiah, K. Sreekanth, D. Kumar, D. Rao","doi":"10.1155/2014/124012","DOIUrl":"https://doi.org/10.1155/2014/124012","url":null,"abstract":"Densities, , and ultrasonic speeds, of mixtures of 1-butanol or iso-butanol or t-butanol with equimolar mixture of (N,N-dimethylacetamide","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"176 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2014-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80676516","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}
This research article reports the experimental results of the density, viscosity, refractive index, and speed of sound analysis of binary mixtures of dimethylsulfoxide (DMSO)
本文报道了二甲基亚砜(DMSO)二元混合物的密度、粘度、折射率和声速分析的实验结果。
{"title":"Thermophysical Properties of Binary Mixtures of Dimethylsulfoxide with 1-Phenylethanone and 1,4-Dimethylbenzene at Various Temperatures","authors":"Harmandeep Singh Gill, V. K. Rattan","doi":"10.1155/2014/607052","DOIUrl":"https://doi.org/10.1155/2014/607052","url":null,"abstract":"This research article reports the experimental results of the density, viscosity, refractive index, and speed of sound analysis of binary mixtures of dimethylsulfoxide (DMSO)","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"8 1","pages":"1-9"},"PeriodicalIF":0.0,"publicationDate":"2014-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89898828","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}
This paper presents the thermal and economic performance of a 210 MWe coal-fired power plant situated in North India. Analysis is used to predict coal consumption rate, overall thermal efficiency, mass flow rate of steam through boiler, and Net present value (NPV) of plant for given load. Thermodynamic analysis was carried out using mass and energy equations followed by empirical correlations. Predicted mass flow rate of steam, coal consumption rate, and thermal efficiency give fair agreement with plant operating data. The economic analysis includes operational activities such as equipment cost, fuel cost, operations and maintenance cost, revenue, and plant net present value. From economic point of view, the effect of condensate extraction pump redundancy on net present value is observed to be sensitive than boiler feed pump redundancy.
{"title":"Thermal Performance and Economic Analysis of 210 MWe Coal-Fired Power Plant","authors":"Ravinder Kumar, Avdhesh Sharma, P. C. Tewari","doi":"10.1155/2014/520183","DOIUrl":"https://doi.org/10.1155/2014/520183","url":null,"abstract":"This paper presents the thermal and economic performance of a 210 MWe coal-fired power plant situated in North India. Analysis is used to predict coal consumption rate, overall thermal efficiency, mass flow rate of steam through boiler, and Net present value (NPV) of plant for given load. Thermodynamic analysis was carried out using mass and energy equations followed by empirical correlations. Predicted mass flow rate of steam, coal consumption rate, and thermal efficiency give fair agreement with plant operating data. The economic analysis includes operational activities such as equipment cost, fuel cost, operations and maintenance cost, revenue, and plant net present value. From economic point of view, the effect of condensate extraction pump redundancy on net present value is observed to be sensitive than boiler feed pump redundancy.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"12 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2014-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78297865","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}
Entropy generation and pumping power to heat transfer ratio (PPR) of a laminar flow, for a circular tube immersed in an isothermal fluid, are studied analytically in this paper. Two different fluids, namely, water and ethylene glycol, are chosen to study the influence of fluid properties on entropy generation and PPR. The expressions for dimensionless entropy generation, Bejan number and PPR are derived in a detailed way and their variations with Reynolds number, external Biot number, and the dimensionless temperature difference are illustrated. The results of the analysis are compared with those for a laminar flow in a circular tube with uniform wall temperature boundary condition. Finally, a criterion is established to determine which type of thermal boundary conditions is more suitable for a particular fluid, with respect to its influence on entropy generation.
{"title":"Second Law Analysis of Laminar Flow in a Circular Pipe Immersed in an Isothermal Fluid","authors":"V. Anand, Krishna Nelanti","doi":"10.1155/2013/234264","DOIUrl":"https://doi.org/10.1155/2013/234264","url":null,"abstract":"Entropy generation and pumping power to heat transfer ratio (PPR) of a laminar flow, for a circular tube immersed in an isothermal fluid, are studied analytically in this paper. Two different fluids, namely, water and ethylene glycol, are chosen to study the influence of fluid properties on entropy generation and PPR. The expressions for dimensionless entropy generation, Bejan number and PPR are derived in a detailed way and their variations with Reynolds number, external Biot number, and the dimensionless temperature difference are illustrated. The results of the analysis are compared with those for a laminar flow in a circular tube with uniform wall temperature boundary condition. Finally, a criterion is established to determine which type of thermal boundary conditions is more suitable for a particular fluid, with respect to its influence on entropy generation.","PeriodicalId":17290,"journal":{"name":"Journal of Thermodynamics","volume":"40 1","pages":"1-10"},"PeriodicalIF":0.0,"publicationDate":"2013-12-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75131430","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}
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