This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is...This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is introduced as the third key element besides the first and second law of thermodynamics. This state space provides the mathematical structure to generalize the Gibbs fundamental relation to non-equilibrium thermodynamics. A unique formulation for the second law of thermodynamics is postulated and it showed how the complying concept for non-equilibrium entropy is retrieved. The foundation of this formulation is a physical quantity, which is in non-equilibrium thermodynamics nowhere equal to zero. This is another perspective compared to the inequality, which is used in most other formulations in the literature. Based on this mathematical framework, it is proven that the thermodynamic potential is defined by the Gibbs free energy. The set of conjugated coordinates in the mathematical structure for the Gibbs fundamental relation will be identified for single component, closed systems. Only in the final section of this contribution will the equilibrium constraint be introduced and applied to obtain some familiar formulations for classical (equilibrium) thermodynamics.展开更多
In this review we explore the recent developments in the use of Magnetic Resonance Imaging(MRI)for studying granular flows.While MRI has been a valuable tool in this field for the past 40 years,recent advances in imag...In this review we explore the recent developments in the use of Magnetic Resonance Imaging(MRI)for studying granular flows.While MRI has been a valuable tool in this field for the past 40 years,recent advances in imaging hardware,reconstruction software and particles synthesis have significantly enhanced its capabilities.This article provides an overview of the current challenges of MRI and progress in the field of granular media,and gives a perspective of the possible future developments in the field.展开更多
Ionic liquids combined with supercriticalfluid technology hold great promise as working solvents for developing compact processes.Ionic liquids,which are organic molten salts,typically have extremely low volatility and...Ionic liquids combined with supercriticalfluid technology hold great promise as working solvents for developing compact processes.Ionic liquids,which are organic molten salts,typically have extremely low volatility and high functionality,but possess high viscos-ities,surface tensions and low diffusion coefficients,which can limit their applicability.CO_(2),on the other hand,especially in its supercritical state,is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer.The solubility of CO_(2) in the ionic liquid is key to estimating the important physical properties that include partition coefficients,viscosities,densities,interfacial tensions,thermal conductivities and heat capacities needed in contactor design.In this work,we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO_(2)-ionic liquid solubility data and report new correlations for CO_(2)-ionic liquid systems with equations of state that have some industrial applications including:(1)general,(2)fuel desulfurization,(3)CO_(2) capture,and(4)chiral separation.New measurements of solubility data for the CO_(2) and 1-butyl-3-methylimidazolium octyl sulfate,[bmim][OcSO4]system are reported and correlated.In the correlation of the CO_(2) ionic liquid phase behavior,the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared.It is shown that excellent correlation of CO_(2) solubility can be obtained with either equation and they share some common characteristics regarding inter-action parameters.In the Sanchez-Lacombe equation,parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO_(2)-ionic liquid solubility data.展开更多
In this work,melting of a high-temperature inorganic phase change material(PCM)eutectic(with a melting point of 569℃)within a vertical cylindrical tank has been experimentally investigated.To promote the heat transfe...In this work,melting of a high-temperature inorganic phase change material(PCM)eutectic(with a melting point of 569℃)within a vertical cylindrical tank has been experimentally investigated.To promote the heat transfer rate,a periodic structure that is constructed by a commercial SS-304 mesh screen has been considered and immersed into the PCM tank.Thermal characteristics of the PCM-periodic structure tank under different initial temperatures(450,490 and 546℃)and wall temperatures(620,640,660,680 and 700℃),are then investigated and reported.The presented experimental data can facilitate practical engineers to find the best operating condition of similar PCM tanks;meanwhile,it can also be employed for the investigation of thermal response of transient heat conduction before melting starts.展开更多
Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular geometries.In this study,the extended KTGF implemented in cylindric...Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular geometries.In this study,the extended KTGF implemented in cylindrical coordinates is used to model the more-commonly employed cylindrical bubbling fluidized beds.Special attention is paid to the anti-symmetric part of the velocity gradient in the solids stress tensor.For verification of the implementation,a comparison of the present model in the limit of zero friction with the original (frictionless) KTGF model was made.Subsequently,simulations of bubbling fluidized beds of inelastic particles were performed using our extended KTGF and an effective KTGF model for inelastic particles of Jenkins and Zhang.The simulation results show good agreement for the time-averaged solids volume fraction distribution and solids circulation patterns.Finally,our model is validated by predicting the individual bubble behavior in dense bubbling fluidized beds containing different granular materials in a comparison with experimental data from Verma et al.(2014).The extended KTGF leads to an improved agreement with experimental bubble data.Compared to previous work (Yang et al.,2016b,2017c),and by introducing cylindrical coordinates,the current work demonstrates that the extended KTGF improves predictions for the temporal bubble behavior of cylindrical fluidized beds.展开更多
文摘This contribution presents an outline of a new mathematical formulation for Classical Non-Equilibrium Thermodynamics (CNET) based on a contact structure in differential geometry. First a non-equilibrium state space is introduced as the third key element besides the first and second law of thermodynamics. This state space provides the mathematical structure to generalize the Gibbs fundamental relation to non-equilibrium thermodynamics. A unique formulation for the second law of thermodynamics is postulated and it showed how the complying concept for non-equilibrium entropy is retrieved. The foundation of this formulation is a physical quantity, which is in non-equilibrium thermodynamics nowhere equal to zero. This is another perspective compared to the inequality, which is used in most other formulations in the literature. Based on this mathematical framework, it is proven that the thermodynamic potential is defined by the Gibbs free energy. The set of conjugated coordinates in the mathematical structure for the Gibbs fundamental relation will be identified for single component, closed systems. Only in the final section of this contribution will the equilibrium constraint be introduced and applied to obtain some familiar formulations for classical (equilibrium) thermodynamics.
文摘In this review we explore the recent developments in the use of Magnetic Resonance Imaging(MRI)for studying granular flows.While MRI has been a valuable tool in this field for the past 40 years,recent advances in imaging hardware,reconstruction software and particles synthesis have significantly enhanced its capabilities.This article provides an overview of the current challenges of MRI and progress in the field of granular media,and gives a perspective of the possible future developments in the field.
基金support of the Monbukagakusho,the Ministry of Education,Culture,Sports,Science and Technology and also that of the Global Education Center of Excellence(GCOE).
文摘Ionic liquids combined with supercriticalfluid technology hold great promise as working solvents for developing compact processes.Ionic liquids,which are organic molten salts,typically have extremely low volatility and high functionality,but possess high viscos-ities,surface tensions and low diffusion coefficients,which can limit their applicability.CO_(2),on the other hand,especially in its supercritical state,is a green solvent that can be used advantageously when combined with the ionic liquid to provide viscosity and surface tension reduction and to promote mass transfer.The solubility of CO_(2) in the ionic liquid is key to estimating the important physical properties that include partition coefficients,viscosities,densities,interfacial tensions,thermal conductivities and heat capacities needed in contactor design.In this work,we examine a subset of available high pressure pure component ionic liquid PVT data and high pressure CO_(2)-ionic liquid solubility data and report new correlations for CO_(2)-ionic liquid systems with equations of state that have some industrial applications including:(1)general,(2)fuel desulfurization,(3)CO_(2) capture,and(4)chiral separation.New measurements of solubility data for the CO_(2) and 1-butyl-3-methylimidazolium octyl sulfate,[bmim][OcSO4]system are reported and correlated.In the correlation of the CO_(2) ionic liquid phase behavior,the Peng-Robinson and the Sanchez-Lacombe equations of state were considered and are compared.It is shown that excellent correlation of CO_(2) solubility can be obtained with either equation and they share some common characteristics regarding inter-action parameters.In the Sanchez-Lacombe equation,parameters that are derived from the supercritical region were found to be important for obtaining good correlation of the CO_(2)-ionic liquid solubility data.
文摘In this work,melting of a high-temperature inorganic phase change material(PCM)eutectic(with a melting point of 569℃)within a vertical cylindrical tank has been experimentally investigated.To promote the heat transfer rate,a periodic structure that is constructed by a commercial SS-304 mesh screen has been considered and immersed into the PCM tank.Thermal characteristics of the PCM-periodic structure tank under different initial temperatures(450,490 and 546℃)and wall temperatures(620,640,660,680 and 700℃),are then investigated and reported.The presented experimental data can facilitate practical engineers to find the best operating condition of similar PCM tanks;meanwhile,it can also be employed for the investigation of thermal response of transient heat conduction before melting starts.
文摘Recently,we have extended the kinetic theory of granular flow (KTGF) to include friction between the spherical particles and tested it in rectangular geometries.In this study,the extended KTGF implemented in cylindrical coordinates is used to model the more-commonly employed cylindrical bubbling fluidized beds.Special attention is paid to the anti-symmetric part of the velocity gradient in the solids stress tensor.For verification of the implementation,a comparison of the present model in the limit of zero friction with the original (frictionless) KTGF model was made.Subsequently,simulations of bubbling fluidized beds of inelastic particles were performed using our extended KTGF and an effective KTGF model for inelastic particles of Jenkins and Zhang.The simulation results show good agreement for the time-averaged solids volume fraction distribution and solids circulation patterns.Finally,our model is validated by predicting the individual bubble behavior in dense bubbling fluidized beds containing different granular materials in a comparison with experimental data from Verma et al.(2014).The extended KTGF leads to an improved agreement with experimental bubble data.Compared to previous work (Yang et al.,2016b,2017c),and by introducing cylindrical coordinates,the current work demonstrates that the extended KTGF improves predictions for the temporal bubble behavior of cylindrical fluidized beds.
