ABSTRACT

Micro wind technology is preferred to satisfy the energy needs of individual in built environment as well as in non-grid connected rural areas due to its several merits. Though, the technology has several advantages but its expansion is very slow due to few significant limitations such as, low efficiency of wind turbines and public concerns regarding safety in the turbine vicinity, noise and visual impact. Various techniques such as wind concentrators, deflectors, and curtains were introduced, time to time, to improve the efficiency of these systems. These techniques improved the efficiency of micro vertical axis wind turbines (VA W T) considerably, but at the cost of their omnidirectional nature. Wind Accelerating and Guiding Rotor House (WAG-RH) is introduced in this study to enhance working range of vertical axis wind turbine in low-speed and turbulent wind locations with improved efficiency. The WAG-RH collects free stream with the parcel of area nearly equal to the projected area of the rotor house then guide, accelerate and concentrate it onto the beneficial location in the space left for vertical axis wind turbine to avoid negative torque and generate more positive torque. Different WAG-RH design concepts were developed and their performance regarding wind speed amplification factor was simulated using design software Gambit version 11.0 and Computational Fluid Dynamic (CFD) educational version of ANSYS fluent 14.5. Four turbulence models such as, K-e(standard), K-m(standard), K-O(SST), and Inviscid were implemented on geometry of WAG-RH. K-O(SST) was found in good agreement with experimental investigation, dedicated to model validation, so was used for further analysis. The optimized configuration of the proposed rotor house contributed nearly 50% increase in inlet velocity in the rotor zone of the rotor house. Experimental investigations regarding performance of optimized configuration of the proposed rotor house to improve efficiency' of the VA WT was performed In this regard, a conventional three bladed Savonius rotor model and the model of optimized design of RH was manufactured and tested under laboratory conditions as well as open air conditions. The present study utilizes other green energy element also by integrating the WAG-RH with a solar heating system. The integration is found capable to improve the performance of rotor setup in the WAG-RH as well as provides hot air with sufficient air mass flow rate for space heating. The WAG-RII contributed 97% increase in the Cp of 3-bladed Savonius rotor whereas, solar integration with WAG-RH, using Vertical -Horizontal Co-axial Blade Combination Technique (VHCBC), improved the Cp, further, to 112% for 5m/s wind speed