Additive manufacturing(AM),also known as 3D-printing(3DP)technology,is an advanced manufacturing technology that has developed rapidly in the past 40 years.However,the ceramic material printing is still challenging be...Additive manufacturing(AM),also known as 3D-printing(3DP)technology,is an advanced manufacturing technology that has developed rapidly in the past 40 years.However,the ceramic material printing is still challenging because of the issue of cracking.Indirect 3D printing has been designed and drawn attention because of its high manufacturing speed and low cost.Indirect 3D printing separates the one-step forming process of direct 3D printing into binding and material sintering,avoiding the internal stress caused by rapid cooling,making it possible to realize the highquality ceramic component with complex shape.This paper presents the research progress of leading indirect 3D printing technologies,including binder jetting(BJ),stereolithography(SLA),and fused deposition modeling(FDM).At present,the additive manufacturing of ceramic materials is mainly achieved through indirect 3D printing technology,and these materials include silicon nitride,hydroxyapatite functional ceramics,silicon carbide structural ceramics.展开更多
The hydrodynamic behavior in a high-density downer reactor was studied. A two-fluid model based on the kinetic theory of granular flow with a k-ε turbulent model was developed to simulate the flow behavior in the sys...The hydrodynamic behavior in a high-density downer reactor was studied. A two-fluid model based on the kinetic theory of granular flow with a k-ε turbulent model was developed to simulate the flow behavior in the system. This simulation achieved an averaged solid fraction in the bed as high as 18% in this operating regime. The flow development in high-density downer consists of 3 regions, which are first acceleration, second acceleration, and fully developed regions. In the fully developed region, the lateral distribution of the solid volume fraction is low and almost uniform in the center region with a high density peak near the wall region. Gas and solid velocities gradually increase toward the wall and form a peak near the wall region. In addition, the solid volume fraction, gas and solid velocities increase with solid circulation rate.展开更多
Y2000-62158 00134111999年 IEEE 形状模型与应用会议录=1999 IEEEproceedings of international conference on shape modelingand applications[会,英]/IEEE Computer Society & theUniversity of Aizy.—IEEE,1999.—281P.(EC)...Y2000-62158 00134111999年 IEEE 形状模型与应用会议录=1999 IEEEproceedings of international conference on shape modelingand applications[会,英]/IEEE Computer Society & theUniversity of Aizy.—IEEE,1999.—281P.(EC)本会议录收集了于1999年3月1日～4日在日本 Aizu-Wakamatsu 召开的第二届国际形状模型与应用研讨会上发表的32篇论文。内容涉及计算形状建模,拓扑学建模,几何学建模,隐式表面,表面建模与重构,样条与内插,形状分析与变换,体积建模。展开更多
基金Project(51901020)supported by the National Natural Science Foundation of ChinaProject(2019JZZY010327)supported by Shandong Key Research and Development Plan,China+1 种基金Project(201942074001)supported by Aeronautical Science Foundation of ChinaProject(FRF-IP-20-05)supported by the Fundamental Research Funds for the Central Universities,China。
文摘Additive manufacturing(AM),also known as 3D-printing(3DP)technology,is an advanced manufacturing technology that has developed rapidly in the past 40 years.However,the ceramic material printing is still challenging because of the issue of cracking.Indirect 3D printing has been designed and drawn attention because of its high manufacturing speed and low cost.Indirect 3D printing separates the one-step forming process of direct 3D printing into binding and material sintering,avoiding the internal stress caused by rapid cooling,making it possible to realize the highquality ceramic component with complex shape.This paper presents the research progress of leading indirect 3D printing technologies,including binder jetting(BJ),stereolithography(SLA),and fused deposition modeling(FDM).At present,the additive manufacturing of ceramic materials is mainly achieved through indirect 3D printing technology,and these materials include silicon nitride,hydroxyapatite functional ceramics,silicon carbide structural ceramics.
文摘The hydrodynamic behavior in a high-density downer reactor was studied. A two-fluid model based on the kinetic theory of granular flow with a k-ε turbulent model was developed to simulate the flow behavior in the system. This simulation achieved an averaged solid fraction in the bed as high as 18% in this operating regime. The flow development in high-density downer consists of 3 regions, which are first acceleration, second acceleration, and fully developed regions. In the fully developed region, the lateral distribution of the solid volume fraction is low and almost uniform in the center region with a high density peak near the wall region. Gas and solid velocities gradually increase toward the wall and form a peak near the wall region. In addition, the solid volume fraction, gas and solid velocities increase with solid circulation rate.
文摘Y2000-62158 00134111999年 IEEE 形状模型与应用会议录=1999 IEEEproceedings of international conference on shape modelingand applications[会,英]/IEEE Computer Society & theUniversity of Aizy.—IEEE,1999.—281P.(EC)本会议录收集了于1999年3月1日～4日在日本 Aizu-Wakamatsu 召开的第二届国际形状模型与应用研讨会上发表的32篇论文。内容涉及计算形状建模,拓扑学建模,几何学建模,隐式表面,表面建模与重构,样条与内插,形状分析与变换,体积建模。
