An algorithm based on the Boundary Element Method(BEM)is presented for designing the High Skew Propeller(HSP)used in an Underwater Vehicle(UV).Since UVs operate under two different kinds of working conditions(i.e.surf...An algorithm based on the Boundary Element Method(BEM)is presented for designing the High Skew Propeller(HSP)used in an Underwater Vehicle(UV).Since UVs operate under two different kinds of working conditions(i.e.surface and submerged conditions),the design of such a propeller is an unwieldy task.This is mainly due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different.Therefore,some factors are necessary for the design of the opti-mum propeller to utilize the power under the mentioned conditions.The design objectives of the optimum propeller are to obtain the highest possible thrust and efficiency with the minimum torque.For the current UV,the main dimensions of the propeller are pre-dicted based on the given required thrust and the defined operating conditions.These dimensions(number of blades,pitch,diameter,expanded area ratio,thickness and camber)are determined through iterative procedure.Because the propeller operates at the stern of the UV where the inflow velocity to the propeller is non-uniform,a 5-blade HSP is preferred for running the UV.Finally,the propel-ler is designed based on the numerical calculations to acquire the improved hydrodynamic efficiency.展开更多
This paper deals with two topics mentioned in the title. First, it is proved that function f in L^P（ Da） can be decomposed into a sum g ＋ h, where Da is an angular domain in the complex plane, g and h are the non-t...This paper deals with two topics mentioned in the title. First, it is proved that function f in L^P（ Da） can be decomposed into a sum g ＋ h, where Da is an angular domain in the complex plane, g and h are the non-tangential limits of functions in H^P（Da） and H^P（aD^c） in the sense of LP（Da）, respectively. Second, the sufficient and necessary conditions between boundary values of holomorphic functions and distributions in n-dimensional complex space are obtained.展开更多
基金supported by the marine research center of Amirkabir University of Technology
文摘An algorithm based on the Boundary Element Method(BEM)is presented for designing the High Skew Propeller(HSP)used in an Underwater Vehicle(UV).Since UVs operate under two different kinds of working conditions(i.e.surface and submerged conditions),the design of such a propeller is an unwieldy task.This is mainly due to the fact that the resistance forces as well as the vessel efficiency under these conditions are significantly different.Therefore,some factors are necessary for the design of the opti-mum propeller to utilize the power under the mentioned conditions.The design objectives of the optimum propeller are to obtain the highest possible thrust and efficiency with the minimum torque.For the current UV,the main dimensions of the propeller are pre-dicted based on the given required thrust and the defined operating conditions.These dimensions(number of blades,pitch,diameter,expanded area ratio,thickness and camber)are determined through iterative procedure.Because the propeller operates at the stern of the UV where the inflow velocity to the propeller is non-uniform,a 5-blade HSP is preferred for running the UV.Finally,the propel-ler is designed based on the numerical calculations to acquire the improved hydrodynamic efficiency.
基金supported by the National Natural Science Foundation of China(No.11271045)the Higher School Doctoral Foundation of China(No.20100003110004)
文摘This paper deals with two topics mentioned in the title. First, it is proved that function f in L^P（ Da） can be decomposed into a sum g ＋ h, where Da is an angular domain in the complex plane, g and h are the non-tangential limits of functions in H^P（Da） and H^P（aD^c） in the sense of LP（Da）, respectively. Second, the sufficient and necessary conditions between boundary values of holomorphic functions and distributions in n-dimensional complex space are obtained.
