Surfaces for fluid suction and ejection in fans, rotors or turbines

摘要

The hub (1) is surrounded by projecting radial blades (3) fixed to its outer sheath (2) and having an S-shaped or sinusoidal cross-section with two vertices (4.1,4.2). The surface geometry of the blades is defined in a cylindrical co-ordinate system by equations involving sine and cosine functions raised to the power of an inner slope constant. The two functions together contribute to a three-dimensional curve. The radius function is modified by a core adaptation constant which can be zero, causing lines of different slope intersecting the family of curves to spring from a common point. Each blade is reduced in external diameter at a step.