Method of designing an Impeller blade

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 ⁡ ( u ) = ∑ k = O k = n ⁢ f k ⁢ B k n ⁡ ( u )
• wherein
• 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(1−u)n−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.