Solid contamination existing as solid particles in power fluid transmission systems may lead to transmission performance reduction,system failures,and component damage.The hydraulic reservoir will deposit the contamin...Solid contamination existing as solid particles in power fluid transmission systems may lead to transmission performance reduction,system failures,and component damage.The hydraulic reservoir will deposit the contamination and store hydraulic fluid.To investigate its purification ability for solid contamination,experiments and simulations for the motion and deposition status of the typical hydraulic system particles are carried out to reveal the interaction of particles and fluid in hydraulic water reservoirs.The results show that the CFD-DEM coupling method could predict the accurate deposition position of iron particles and sand particles when ignoring the small-scale turbulence effect in the flow field.Besides,the particle motion traces and deposition patterns in the reservoir illustrate that the flow development on the bottom surface results in the particles turning,and particles tend to settle in the low flow energy position.The motion of particles is also linked to particles Stokes number,and the same-size sand particles are easily driven by the fluid.The contribution of this paper could provide a guide for predicting the particle motion and deposition pattern in the hydraulic reservoir.展开更多
With the increasing demand to reduce emissions and save energy,hydraulic reservoirs require new architecture to optimize their weight,space,and volume.Conventional open reservoirs are large,heavy,and easily polluted,a...With the increasing demand to reduce emissions and save energy,hydraulic reservoirs require new architecture to optimize their weight,space,and volume.Conventional open reservoirs are large,heavy,and easily polluted,and threaten the operation of hydraulic systems.A closed reservoir provides the advantages of small volume and light weight,compared to open reservoirs.In this study,a non-metallic pressure reservoir with variable volume is designed and manufactured for closed-circuit hydraulic systems.The reservoir housing is made of rubber,and the Mooney-Rivlin model is chosen based on the rubber strain properties.The FEA simulation for the reservoir is performed using ANSYS Workbench to obtain the structural stiffness.The major contribution is the establishment of mathematical models for this reservoir,including the volume equation changing with height,flow equation,and force balance equation,to explore the output characteristics of this reservoir.Based on these results,simulation models were built to analyze the output characteristics of the reservoir.Moreover,the test rig of a conventional hydraulic system was transformed into a closed-circuit asymmetric hydraulic system for the reservoir,and preliminary verification experiments were conducted on it.The results demonstrate that the designed reservoir can absorb and discharge oil and supercharge pump inlet to benefit system operation.The changes in the volume and pressure with displacements under different volume ratios and frequencies were obtained,which verified the accuracy of the mathematical models.Owing to its lightweight design and small volume,the reservoir can replace conventional open reservoirs,and this lays a foundation for future theoretical research on this reservoir.展开更多
In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.B...In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.By heating the chloroform(CF)solution to 70℃(slightly above the boiling point of CF,~61.2℃),an optimal balance between solvent evaporation and molecular self-assembly was achieved,resulting in enhanced crystallinity,favorable π-π stacking,and ideal nanoscale phase separation.These improvements significantly boost the power conversion efficiency from 17.74%(for the device processed at a room temperature of 30℃)to 19.56%.Moreover,the in-situ grazing-incidence wide-angle X-ray scattering technology was utilized to monitor the crystallization and morphology evolution of the active layer,offering real-time insights into molecule self-assembly and phase separation dynamics during active layer solidification.This work not only provides a simple and scalable approach for fabricating high-efficiency OSCs but also offers fundamental insights into the influence of solution temperature on active layer morphology evolution dynamics,paving the way for large-scale industrial production of organic solar cells.展开更多
基金National Key Research and Development Program of China(Grant No.2018YFB2000703)National Natural Science Foundation of China(Grant No.51975507).
文摘Solid contamination existing as solid particles in power fluid transmission systems may lead to transmission performance reduction,system failures,and component damage.The hydraulic reservoir will deposit the contamination and store hydraulic fluid.To investigate its purification ability for solid contamination,experiments and simulations for the motion and deposition status of the typical hydraulic system particles are carried out to reveal the interaction of particles and fluid in hydraulic water reservoirs.The results show that the CFD-DEM coupling method could predict the accurate deposition position of iron particles and sand particles when ignoring the small-scale turbulence effect in the flow field.Besides,the particle motion traces and deposition patterns in the reservoir illustrate that the flow development on the bottom surface results in the particles turning,and particles tend to settle in the low flow energy position.The motion of particles is also linked to particles Stokes number,and the same-size sand particles are easily driven by the fluid.The contribution of this paper could provide a guide for predicting the particle motion and deposition pattern in the hydraulic reservoir.
基金Supported by the National Key Research and Development Program of China(Grant No.2018YFB2000700)National Natural Science Foundation of China(Grant No.51890811).
文摘With the increasing demand to reduce emissions and save energy,hydraulic reservoirs require new architecture to optimize their weight,space,and volume.Conventional open reservoirs are large,heavy,and easily polluted,and threaten the operation of hydraulic systems.A closed reservoir provides the advantages of small volume and light weight,compared to open reservoirs.In this study,a non-metallic pressure reservoir with variable volume is designed and manufactured for closed-circuit hydraulic systems.The reservoir housing is made of rubber,and the Mooney-Rivlin model is chosen based on the rubber strain properties.The FEA simulation for the reservoir is performed using ANSYS Workbench to obtain the structural stiffness.The major contribution is the establishment of mathematical models for this reservoir,including the volume equation changing with height,flow equation,and force balance equation,to explore the output characteristics of this reservoir.Based on these results,simulation models were built to analyze the output characteristics of the reservoir.Moreover,the test rig of a conventional hydraulic system was transformed into a closed-circuit asymmetric hydraulic system for the reservoir,and preliminary verification experiments were conducted on it.The results demonstrate that the designed reservoir can absorb and discharge oil and supercharge pump inlet to benefit system operation.The changes in the volume and pressure with displacements under different volume ratios and frequencies were obtained,which verified the accuracy of the mathematical models.Owing to its lightweight design and small volume,the reservoir can replace conventional open reservoirs,and this lays a foundation for future theoretical research on this reservoir.
基金financially supported by the National Natural Science Foundation of China(61705003)。
文摘In this study,high-performance D18:L8-BO bulk heterojunction organic solar cells(OSCs)were prepared by employing a hot-solution strategy to optimize the active layer morphology during the film solidification process.By heating the chloroform(CF)solution to 70℃(slightly above the boiling point of CF,~61.2℃),an optimal balance between solvent evaporation and molecular self-assembly was achieved,resulting in enhanced crystallinity,favorable π-π stacking,and ideal nanoscale phase separation.These improvements significantly boost the power conversion efficiency from 17.74%(for the device processed at a room temperature of 30℃)to 19.56%.Moreover,the in-situ grazing-incidence wide-angle X-ray scattering technology was utilized to monitor the crystallization and morphology evolution of the active layer,offering real-time insights into molecule self-assembly and phase separation dynamics during active layer solidification.This work not only provides a simple and scalable approach for fabricating high-efficiency OSCs but also offers fundamental insights into the influence of solution temperature on active layer morphology evolution dynamics,paving the way for large-scale industrial production of organic solar cells.
