Incorporation of Sweep in a Transonic Fan Design Using a 3D Blade-Row GeometryPackage Intended for Aero-Structural-Manufacturing Optimization

摘要

A new 3D blade row geometry package was developed and implemented. In the newrepresentation the blade is described by six Bezier surfaces two of which represent the pressure and suction surfaces with sixteen points each. The leading and trailing edges are each represented by two Bezier surfaces. Only one extra parameter is required (in addition to the pressure and suction surfaces parameters) to define each of the leading and trailing edge surfaces. Blade geometry manipulation in this format is easily implemented. A change to one surface location affects the surrounding area inversely proportional to the distance from the moved point, creating a smooth variation in geometry, free of waviness. The geometry generated is easy to handle with CAD/CAM programs without any conversion or approximation. The representation was applied to an existing transonic fan geometry to investigate effects of sweep. Results were obtained for the effect of forward and backward sweep on the aerodynamic performance, and the associated effect on centrifugal stress levels was obtained. The investigation demonstrated the suitability of the package to be incorporated into a multi-disciplinary design optimization process.