Patent ID: 6616409
Filing Date: 2003-09-09
Classification: F04D,H02K,Y10S

Abstract:
A method for determining an optimum camber line and thickness distributions in a blade for an impeller having a root portion, a tip portion, a leading edge and a trailing edge, comprising the steps of:determining a series of fan performance parameters and design constraints; utilization of Bezier curves to determine the appropriate camber line and thickness distributions utilizing the equation F&af;(u)=&Sum;k=Ok=n&it;fk&it;Bkn&af;(u)â€ƒwherein F(u) represents the solution of the Bezier curve; u is a parameter that varies linearly between 0 and 1, (u=0 at the leading edge and u=1 at the trailing edge); fk is a one-dimensional array of Bezier control points; Bkn(u) is the Bernstein polynomial of degree n; Bkn(u)=(kn)uk(1âˆ’u)nâˆ’k; n+1 is the number of Bezier control points, and (kn) are the binomial coefficients as defined in CRC Standard Mathematical Tables, 22nd Ed., 1974, p. 627; initial values of the Bezier control points are selected; F(u) is separately applied to determine the camber line x and y coordinates as well as the thickness distribution; conducting an inviscid flow analysis of the to determine a surface velocity distribution and work distribution for the resultant camber line and thickness distributions; altering the Bezier control points, acquiring different camber and thickness distributions, repeating the process until a favorable solution is achieved.