Computational modeling of ducted wind turbines for residential applications

As wind turbines are increasingly being adopted for meeting growing energy needs, their implementation for personal home use in the near future is imminent. There are very few studies conducted on these small-scale turbines in the one to two meter diameter range because the power generated at this scale is not sufficient to justify the cost of installation and maintenance. The problem is further complicated by the fact that these turbines are normally mounted at low altitudes and thus there is necessity to have the optimum operating regime in the wind speed range of 3-10 mph (1.34 - 4.47 m/s). This study analyzes the turbine performance with a diffuser at these dimensions and demonstrates the pathway that can meet these challenges. The design was modeled using commercial computational fluid dynamics code. Two-dimensional modeling using actuator disk theory was used to optimize the diffuser design. A statistical study was then conducted to reduce the computational time by selecting a descriptive set of models to test and characterize the effect of prominent parameters rather than evaluating all the possible combinations of input parameters. Individual dimensions were incorporated into JMP software and randomized to design the experiment. The results of the JMP analysis are discussed in this paper. Consistent with the literature, a long outlet section (one to three times the length of the diameter) coupled with a sharp angled inlet was found to provide the highest amplification for a wind turbine diffuser.