The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate th...The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate that when the circular rings cover near 2/3 of the width of the blade tips of the rotor in the axis direction,the rotor has the lowest OASPL and the related total pressure efficiency and flow mass rate are better than the corresponding values obtained for a reference rotor without a circular ring.With increasing the width of the circular ring in the axis direction,the tip vortex around the trailing edge of the blade tip becomes smaller and finally disappears.Meanwhile,a separated flow field arises gradually and then grows in size around the middle of the junction of the blade tips with the ring.When the circular rings cover nearly 2/3 s of the width of the blade tips of the fan in the axis direction,the extension of the separated flow around the blade’s tip attains a minimum.展开更多
Achieving sustainable patterns of consumption and production is perhaps the biggest challenge facing our society today. The de-mand for more safe environmentally benign products is rising and many companies are lookin...Achieving sustainable patterns of consumption and production is perhaps the biggest challenge facing our society today. The de-mand for more safe environmentally benign products is rising and many companies are looking for new ways to progressively improve the sus-tainability of their products. Moreover, there are numerous opportunities and countless innovations, technological as well as non-technologi-cal,that need to be exploited to improve the sustainability of products. Manufacturing industry is an important sector of any economy and hasthe potential to become a driving force for enabling sustainable patterns of production and consumption through introducing efficient productionpractices and developing products and services that help reduce environmental impacts. The benefits of adopting an integrated policy towardsproduct development based on life cycle thinking and eco-design to stimulate improvement of the environmental performance of each part ofproduct life cycle phases and achieve sustainable patterns of production and consumption are emphasized. The challenges in implementingsustainable manufacturing and the circular economy approaches are listed. A number of solutions are suggested to face up these challenges,for instance, increased awareness of enterprises particularly SME's of product life cycle issues and the opportunities that are available for costsavings and profit making from eco-innovation in product development for both the domestic and export markets and providing practical helpand advice directly to enterprises on integrated product development to promote enterprise led Eco-innovation. Aiming at contributing to sus-tainable manufacturing in China, Sino-UK Low Carbon Manufacturing Consortium, a multi-disciplinary research and educational partnershipbetween academia, industry and government agencies in the UK and China with interest in sustainable manufacturing issues, has been formedrecently.The vision, aims and benefits of membership of the consortium are also discussed.展开更多
The availability of the plastid genome sequences is one of the bases for comparative,functional,and structural genomic studies of plastid-containing living organisms,in addition to the application
The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytic...The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.展开更多
基金supported by the Guiding Project of Scientific Research Plan of Hubei Education Department of China[Grant No.B2020227].
文摘The influence of the width of the circular ring of a car cooling fan on the aerodynamic noise is investigated numerically through the determination of the overall sound pressure level(OASPL).The results demonstrate that when the circular rings cover near 2/3 of the width of the blade tips of the rotor in the axis direction,the rotor has the lowest OASPL and the related total pressure efficiency and flow mass rate are better than the corresponding values obtained for a reference rotor without a circular ring.With increasing the width of the circular ring in the axis direction,the tip vortex around the trailing edge of the blade tip becomes smaller and finally disappears.Meanwhile,a separated flow field arises gradually and then grows in size around the middle of the junction of the blade tips with the ring.When the circular rings cover nearly 2/3 s of the width of the blade tips of the fan in the axis direction,the extension of the separated flow around the blade’s tip attains a minimum.
文摘Achieving sustainable patterns of consumption and production is perhaps the biggest challenge facing our society today. The de-mand for more safe environmentally benign products is rising and many companies are looking for new ways to progressively improve the sus-tainability of their products. Moreover, there are numerous opportunities and countless innovations, technological as well as non-technologi-cal,that need to be exploited to improve the sustainability of products. Manufacturing industry is an important sector of any economy and hasthe potential to become a driving force for enabling sustainable patterns of production and consumption through introducing efficient productionpractices and developing products and services that help reduce environmental impacts. The benefits of adopting an integrated policy towardsproduct development based on life cycle thinking and eco-design to stimulate improvement of the environmental performance of each part ofproduct life cycle phases and achieve sustainable patterns of production and consumption are emphasized. The challenges in implementingsustainable manufacturing and the circular economy approaches are listed. A number of solutions are suggested to face up these challenges,for instance, increased awareness of enterprises particularly SME's of product life cycle issues and the opportunities that are available for costsavings and profit making from eco-innovation in product development for both the domestic and export markets and providing practical helpand advice directly to enterprises on integrated product development to promote enterprise led Eco-innovation. Aiming at contributing to sus-tainable manufacturing in China, Sino-UK Low Carbon Manufacturing Consortium, a multi-disciplinary research and educational partnershipbetween academia, industry and government agencies in the UK and China with interest in sustainable manufacturing issues, has been formedrecently.The vision, aims and benefits of membership of the consortium are also discussed.
文摘The availability of the plastid genome sequences is one of the bases for comparative,functional,and structural genomic studies of plastid-containing living organisms,in addition to the application
文摘The swelling behavior of a temperature-sensitive poly-N-isopropylacrylamide(PNIPAM) hydrogel circular cylinder is studied subjected to combined extension-torsion and varied temperature. In this regard, a semi-analytical solution is proposed for general combined loading. A finite element(FE) analysis is conducted, subjecting a hydrogel cylinder to the combined extension-torsion and the varied temperature to evaluate the validity and accuracy of the solution. A user-defined UHYPER subroutine is developed and verified under free and constrained swelling conditions. The FE results illustrate excellent agreement with the semi-analytical solution. Due to the complexity of the problem, some compositions and applied loading factors are analyzed. It is revealed that for larger cross-linked density and larger ending temperature, the cylinder yields higher stresses and smaller radial swelling deformation. Besides, the radial and hoop stresses increase by applying larger twist and axial stretch. The hoop stresses intersect at approximately R/Rout = 0.58, where the hoop stress vanishes. Besides, the axial force has direct and inverse relationships with the axial stretch and the twist, respectively. However, the resultant torsional moment behavior is complex, and the position of the maximum point varies significantly by altering the axial stretch and the twist.
