This paper studies a numerical solution of multiple hole problem by using a boundary integral equation.The studied problem can be considered as a supposition of many single hole problems.After considering the interact...This paper studies a numerical solution of multiple hole problem by using a boundary integral equation.The studied problem can be considered as a supposition of many single hole problems.After considering the interaction among holes,an algebraic equation is formulated,which is then solved by using an iteration technique.The hoop stress around holes can be finally determined. One numerical example is provided to check its accuracy.展开更多
Hydrodynamic cavitation is a new technique in wastewater treatment processes. The degradation of Rbodamine B was studied on a 220 liters hydrodynamic cavitation setup using multiple hole orifice plates in this paper. ...Hydrodynamic cavitation is a new technique in wastewater treatment processes. The degradation of Rbodamine B was studied on a 220 liters hydrodynamic cavitation setup using multiple hole orifice plates in this paper. The experimental results showed that Rhodamine B was really decomposed by hydrodynamic cavitation. Some factors influencing degradation effect i.e. geometric parameters and operation conditions also were discussed. It was concluded there was the optimal ratio of total area of holes to crosssectional area of the pipe and the rate constant increased with a reduction in the value of the modified cavitional number.展开更多
Surface accuracy directly affects the surface quality and performance of mechanical parts.Circular hole,especially spatial non-planar hole set is the typical feature and working surface of mechanical parts.Compared wi...Surface accuracy directly affects the surface quality and performance of mechanical parts.Circular hole,especially spatial non-planar hole set is the typical feature and working surface of mechanical parts.Compared with traditional machining methods,additive manufacturing(AM)technology can decrease the surface accuracy errors of circular holes during fabrication.However,an accuracy error may still exist on the surface of circular holes fabricated by AM due to the influence of staircase effect.This study proposes a surface accuracy optimization approach for mechanical parts with multiple circular holes for AM based on triangular fuzzy number(TFN).First,the feature lines on the manifold mesh are extracted using the dihedral angle method and normal tensor voting to detect the circular holes.Second,the optimal AM part build orientation is determined using the genetic algorithm to optimize the surface accuracy of the circular holes by minimizing the weighted volumetric error of the part.Third,the corresponding weights of the circular holes are calculated with the TFN analytic hierarchy process in accordance with the surface accuracy requirements.Lastly,an improved adaptive slicing algorithm is utilized to reduce the entire build time while maintaining the forming surface accuracy of the circular holes using digital twins via virtual printing.The effectiveness of the proposed approach is experimentally validated using two mechanical models.展开更多
文摘This paper studies a numerical solution of multiple hole problem by using a boundary integral equation.The studied problem can be considered as a supposition of many single hole problems.After considering the interaction among holes,an algebraic equation is formulated,which is then solved by using an iteration technique.The hoop stress around holes can be finally determined. One numerical example is provided to check its accuracy.
文摘Hydrodynamic cavitation is a new technique in wastewater treatment processes. The degradation of Rbodamine B was studied on a 220 liters hydrodynamic cavitation setup using multiple hole orifice plates in this paper. The experimental results showed that Rhodamine B was really decomposed by hydrodynamic cavitation. Some factors influencing degradation effect i.e. geometric parameters and operation conditions also were discussed. It was concluded there was the optimal ratio of total area of holes to crosssectional area of the pipe and the rate constant increased with a reduction in the value of the modified cavitional number.
基金supported by the National Natural Science Foundation of China(Grant Nos.51775494,51821093,and 51935009)the National Key R&D Program of China(Grant No.2018YFB1700701)+1 种基金the Science and Technology Project of Zhejiang Province,China(Grant No.2019C01141)the Zhejiang Provincial Basic Public Welfare Research Project,China(Grant Nos.LGG18E050007 and LGG21E050020).
文摘Surface accuracy directly affects the surface quality and performance of mechanical parts.Circular hole,especially spatial non-planar hole set is the typical feature and working surface of mechanical parts.Compared with traditional machining methods,additive manufacturing(AM)technology can decrease the surface accuracy errors of circular holes during fabrication.However,an accuracy error may still exist on the surface of circular holes fabricated by AM due to the influence of staircase effect.This study proposes a surface accuracy optimization approach for mechanical parts with multiple circular holes for AM based on triangular fuzzy number(TFN).First,the feature lines on the manifold mesh are extracted using the dihedral angle method and normal tensor voting to detect the circular holes.Second,the optimal AM part build orientation is determined using the genetic algorithm to optimize the surface accuracy of the circular holes by minimizing the weighted volumetric error of the part.Third,the corresponding weights of the circular holes are calculated with the TFN analytic hierarchy process in accordance with the surface accuracy requirements.Lastly,an improved adaptive slicing algorithm is utilized to reduce the entire build time while maintaining the forming surface accuracy of the circular holes using digital twins via virtual printing.The effectiveness of the proposed approach is experimentally validated using two mechanical models.
