Blade shape creation program and method

Abstract

In a blade shape creation program and method, a blade thickness function defining equation is constructed by a cubic function as a first function defining a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and a cubic function as a second function defining a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point; is defined, with a camber line length, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.

1 . A blade shape creation program for creating a blade shape on a space virtually defined by a computer, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by    a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and    a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function.    
   
   
       2 . The blade shape creation program according to  claim 1 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       3 . A blade shape creation method for creating a blade shape on a virtually defined space, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by    a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and    a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function.    
   
   
       4 . The blade shape creation method according to  claim 3 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       5 . A blade shape creation program for creating a blade shape on a space virtually defined by a computer, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function, and    in the first function and the second function of the blade thickness function defining equation, a value of the blade thickness is calculated over an entire region of the blade thickness function, and the calculated blade thickness value is compared with a maximum blade thickness value set as a design factor to check whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value.    
   
   
       6 . A blade shape creation program for creating a blade shape on a space virtually defined by a computer, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function, and    the first function and the second function of the blade thickness function defining equation are differentiated to check over an entire region of the blade thickness function whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than a position of maximum blade thickness set as a design factor.    
   
   
       7 . The blade shape creation program according to  claim 5 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       8 . The blade shape creation program according to  claim 6 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       9 . The blade shape creation program according to  claim 5 , wherein 
 results of checking whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value, or results of checking whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than the position of maximum blade thickness are displayed on a checklist window.    
   
   
       10 . The blade shape creation program according to  claim 6 , wherein 
 results of checking whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value, or results of checking whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than the position of maximum blade thickness are displayed on a checklist window.    
   
   
       11 . A blade shape creation method for creating a blade shape on a virtually defined space, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function, and    in the first function and the second function of the blade thickness function defining equation, a value of the blade thickness is calculated over an entire region of the blade thickness function, and the calculated blade thickness value is compared with a maximum blade thickness value set as a design factor to check whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value.    
   
   
       12 . A blade shape creation method for creating a blade shape on a virtually defined space, wherein 
 a blade thickness function defining equation for defining a blade thickness function representing a change in a blade thickness to be defined on a cross section of the blade shape is constructed by a first function which defines a leading edge blade thickness function on a leading edge side of a maximum blade thickness point of the blade thickness function, and a second function which defines a trailing edge blade thickness function on a trailing edge side of the maximum blade thickness point of the blade thickness function, and    the first function and the second function of the blade thickness function defining equation are differentiated to check over an entire region of the blade thickness function whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than a position of maximum blade thickness set as a design factor.    
   
   
       13 . The blade shape creation method according to  claim 11 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       14 . The blade shape creation method according to  claim 12 , wherein the blade thickness function defining equation 
 has the first function and the second function each defined by a cubic function,    is defined, with a camber line length of a section of the blade shape, a position of maximum blade thickness, a maximum blade thickness value, a leading edge blade thickness change rate, a trailing edge blade thickness change rate, a leading edge blade thickness value, and a trailing edge blade thickness value being taken as design factors, and    has a boundary condition that the first function and the second function have tangents continuous with each other at the maximum blade thickness point.    
   
   
       15 . The blade shape creation method according to  claim 11 , wherein 
 results of checking whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value, or results of checking whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than the position of maximum blade thickness are displayed on a checklist.    
   
   
       16 . The blade shape creation method according to  claim 12 , wherein 
 results of checking whether the blade thickness function has a blade thickness value larger than the maximum blade thickness value, or results of checking whether the blade thickness function has a maximum or minimum point or an inflection point at a position other than the position of maximum blade thickness are displayed on a checklist.