Parameter selection and derivative conditions for B-splines applied to gas turbine blade modeling

Abstract: In gas turbine blade modeling a stable but yet flexible method of describing the blade shape is crucial. Polynomials and B ́ezier curves have previously been used and in this paper B-splines are employed instead. This method removes the need for many of the interior derivative conditions on the curve but special care must be taken when selecting the parameter values and appropriate derivative conditions. This paper presents several parameter selection methods and shows how they affect the construction of the curve. In the end a satisfactory curve is produced where one of its conditions depends on a variable whose value can be set to optimize the shape of the curve in the modeling procedure.