A novel and economic rotor hub configuration for small wind turbines

Abstract

The study puts forward a new and economic rotor hub configuration for small wind turbines. With the use of the proposed idea, the required size of timber blanks from which the blades are cut is reduced, leading to the reduction in blanks cost as well as machining process cost. To investigate the presented scheme from the structural aspect, the finite-element analysis was done on a 1 kW turbine rotor hub. The results reveal the applicability of the proposed hub as it could withstand the aerodynamic and centrifugal loadings. From the economic perspective, the cost reduction in the timber blanks and machining process is about 33% and 58% respectively compared to the conventional hub used in small turbines. This would be of interest in promoting the use of small turbines in developing countries where the cost of renewable energies is not competitive with non-renewable ones. Moreover, by using this new hub, the subtraction (machining) mass of timber during the machining process is reduced noticeably, rendering the presented hub configuration interesting from the environmental aspect. Also provided by this new configuration is the starting improvement of the turbine thanks to the lower value of the rotor inertia compared to the conventional configuration.