pathway for fluid passing through the housing such fans comprise a rotor which is normally provided with a plurality of vanes or blades although a rotor having a single blade is possible the vanes are generally configured to provide an outward or radial component of acceleration to the fluid being driven or in the case of a turbine the fluid is deflected to provide a radial component to the force applied to the vane and thereby a deflection to the fluid including a radial component nature provides excellent models of optimized streamlining drag reduction and noise reduction any biological surface grown or eroded to optimize streamlining has no angled corners and does not make fluid turn at right angles but generally follows the shape of an eddy constructed in accordance with a three dimensional equiangular or golden ratio spiral the underlying geometry of this spiral is also found in the design of a bird 39 s egg a snail and a sea shell these spirals or vortices generally comply with a mathematical progression known as the golden ratio or a fibonacci like progression each of the embodiments in the greater part serves to enable fluids to move in their naturally preferred way thereby reducing inefficiencies created through turbulence and friction which are normally found in housings for centrifugal fans previously developed technologies have generally been less compliant with natural fluid flow tendencies it has been found that it is a characteristic of fluid flow that when it is caused to flow in a vortical motion through a pathway that.