In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher t...In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.展开更多
Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat...Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat source, instantaneous point fluid source and constant volume force. By using the so-called fictitious heat source method and images method, the solutions of a semi-infinite saturated porous medium subjected to a local heat source with time-varied intensity on its free surface are developed from elementary solutions. The numerical integral methods for calculating the unsteady temperature, pore pressure and displacement fields are given. The thermomechanical response are analyzed for the case of a circular planar heat source. Besides, the thermal consolidation characteristics of a saturated porous medium subjected to a harmonic thermal loading are also given, and the fluctuation processes of the field variables located below the center of heat source are analyzed.展开更多
With the shadowgraph method, three ultrasonic pulses in Water, which correspond to the conversion modes of the fast compressional wave, the transverse wave and the slow compressional wave in the sample of Fluid-Satura...With the shadowgraph method, three ultrasonic pulses in Water, which correspond to the conversion modes of the fast compressional wave, the transverse wave and the slow compressional wave in the sample of Fluid-Saturated Porous Medium (FSPM) respectively,were observed and recorded by CCD camera. The positions of these pulses are cousistent with the computed positions and the time interval between these pulses measured by a transmitterreceiver method.展开更多
The shape of particles has a significant influence on the behavior of suspensions,as the particle-fluid,particle-particle,and particle-wall interactions depend on it.However,the simultaneous consideration of complex p...The shape of particles has a significant influence on the behavior of suspensions,as the particle-fluid,particle-particle,and particle-wall interactions depend on it.However,the simultaneous consideration of complex particle shapes and four-way coupling remains a major challenge.This is mainly due to a lack of suitable contact models.Contact models for complex shapes have been proposed in literature,and most limit the accuracy of the particle-fluid interaction.For this reason,this paper presents a novel contact model for complex convex particle shapes for use with partially saturated methods,in which we propose to obtain necessary contact properties,such as the indentation depth,by a discretization of the contact area.The goal of the proposed model is to enable comprehensive and accurate studies of particulate flows,especially with high volume fractions,that lead to new insights and contribute to the improvement of existing industrial processes.To ensure correctness and sustainability,we validate the model extensively by studying cases with and without fluid.In the latter case,we use the homogenized lattice Boltzmann method.The provided investigations show a great agreement of the proposed discrete contact model with analytical solutions and the literature.展开更多
In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin （Asp-β-CD） inclusion complex using design of experiment （DOE） methodology. A 3-level, 3-factor Box-B...In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin （Asp-β-CD） inclusion complex using design of experiment （DOE） methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.展开更多
A numerical model is developed to simulate saturated granular soil, based on the discrete element method. Soil particles are represented by Lagrangian discrete elements, and pore fluid, by appropriate discrete element...A numerical model is developed to simulate saturated granular soil, based on the discrete element method. Soil particles are represented by Lagrangian discrete elements, and pore fluid, by appropriate discrete elements which represent alternately Lagrangian mass of water and Eulerian volume of space. Macroscale behavior of the model is verified by simulating undrained biaxial compression tests. Micro-scale behavior is compared to previous literature through pore pressure pattern visualization during shear tests. It is demonstrated that dynamic pore pressure patterns are generated by superposed stress waves. These pore-pressure patterns travel much faster than average drainage rate of the pore fluid and may initiate soil fabric change, ultimately leading to liquefaction in loose sands. Thus, this work demonstrates a tool to roughly link dvnamic stress wave patterns to initiation of liQuefaction nhenomena.展开更多
基金This work was supported in part by the National Natural Science Foundation of China(51707083)in part by the Natural Science Foundation of Jiangsu Province(BK20190848)+1 种基金in part by the China Postdoctoral Science Foundation(2019M661746)by the Priority Academic Program Development of Jiangsu Higher Education Institutions.
文摘In traditional analytical method(AM),the magnetic saturation is always ignored to simplify the calculation process.However,synchronous reluctance motors(SynRMs)often operate around saturation point to achieve higher torque density.Therefore,a new AM is proposed,in which the saturation of stator iron has been considered.The key of the proposed method includes a saturation factor,and an iterative method is adopted to compute the saturation factor in the SynRM by increasing the air-gap length.Especially,the proposed AM can be applied to a SynRM even with shifted-asymmetrical-salient-poles.In the process of AM,the expression of stator magnetomotive force(MMF)is built firstly.Additionally,the air-gap density including slotting effect and salient-poles is calculated.Then,the rotor MMF under saturation of the stator iron is obtained.Therefore,the precision of the instantaneous torque can be improved significantly.Eventually,by the verification of finite elements method(FEM)and experiments,the torque performance of SynRMs with shifted asymmetrical rotor can be predicted accurately by the proposed AM.
基金The project supported by the National Natural Science Foundation of China (50578008) The English text was polished by Yunming Chen
文摘Heat source function method is adopted in the present paper to derive elementary solutions of coupled thermo-hydro-mechanical consolidation for saturated porous media under conjunct actions of instantaneous point heat source, instantaneous point fluid source and constant volume force. By using the so-called fictitious heat source method and images method, the solutions of a semi-infinite saturated porous medium subjected to a local heat source with time-varied intensity on its free surface are developed from elementary solutions. The numerical integral methods for calculating the unsteady temperature, pore pressure and displacement fields are given. The thermomechanical response are analyzed for the case of a circular planar heat source. Besides, the thermal consolidation characteristics of a saturated porous medium subjected to a harmonic thermal loading are also given, and the fluctuation processes of the field variables located below the center of heat source are analyzed.
文摘With the shadowgraph method, three ultrasonic pulses in Water, which correspond to the conversion modes of the fast compressional wave, the transverse wave and the slow compressional wave in the sample of Fluid-Saturated Porous Medium (FSPM) respectively,were observed and recorded by CCD camera. The positions of these pulses are cousistent with the computed positions and the time interval between these pulses measured by a transmitterreceiver method.
基金The research leading to these results was conducted during the IGF Project AiF 21096 N of the FEI that has been supported via AiF within the programme for promoting the Industrial Collective Research(IGF)of the Federal Ministry of Economic Affairs and Climate Action(BMWK)based on a resolution of the German Parliament.
文摘The shape of particles has a significant influence on the behavior of suspensions,as the particle-fluid,particle-particle,and particle-wall interactions depend on it.However,the simultaneous consideration of complex particle shapes and four-way coupling remains a major challenge.This is mainly due to a lack of suitable contact models.Contact models for complex shapes have been proposed in literature,and most limit the accuracy of the particle-fluid interaction.For this reason,this paper presents a novel contact model for complex convex particle shapes for use with partially saturated methods,in which we propose to obtain necessary contact properties,such as the indentation depth,by a discretization of the contact area.The goal of the proposed model is to enable comprehensive and accurate studies of particulate flows,especially with high volume fractions,that lead to new insights and contribute to the improvement of existing industrial processes.To ensure correctness and sustainability,we validate the model extensively by studying cases with and without fluid.In the latter case,we use the homogenized lattice Boltzmann method.The provided investigations show a great agreement of the proposed discrete contact model with analytical solutions and the literature.
文摘In this work, the optimal clathration condition was investigated for the preparation of aspirin-β-cyclodextrin （Asp-β-CD） inclusion complex using design of experiment （DOE） methodology. A 3-level, 3-factor Box-Behnken design with a total of 17 experimental runs was used. The Asp-β-CD inclusion complex was prepared by saturated solution method. The influence on the embedding rate was investigated, including molar ratio of β-CD to Asp, clathration temperature and clathration time, and the optimum values of such three test variables were found to be 0.82, 49C and 2.0 h, respectively. The embedding rate could be up to 61.19%. The formation of the bonding between -COOH group of Asp and O-H group of β-CD might play an important role in the process of clathration according to FT-IR spectra. Release kinetics of Asp from inclusion complex was studied for the evaluation of drug release mechanism and diffusion coefficients. The results showed that the drug release from matrix occurred through Fickian diffusion mechanism. The cumulative release of Asp reached only 40% over 24 h, so the inclusion complex could potentially be applied as a long-acting delivery system.
文摘A numerical model is developed to simulate saturated granular soil, based on the discrete element method. Soil particles are represented by Lagrangian discrete elements, and pore fluid, by appropriate discrete elements which represent alternately Lagrangian mass of water and Eulerian volume of space. Macroscale behavior of the model is verified by simulating undrained biaxial compression tests. Micro-scale behavior is compared to previous literature through pore pressure pattern visualization during shear tests. It is demonstrated that dynamic pore pressure patterns are generated by superposed stress waves. These pore-pressure patterns travel much faster than average drainage rate of the pore fluid and may initiate soil fabric change, ultimately leading to liquefaction in loose sands. Thus, this work demonstrates a tool to roughly link dvnamic stress wave patterns to initiation of liQuefaction nhenomena.
