Computational Fluid Dynamics Studies on the Wind Speed Characteristics of an Improved Diffuser Design

During the following decades, the Diffuser Augmented Wind Turbine (DAWT) concept has attracted continuous interest as an appropriate concept by the modern Horizontal Axis Wind Turbine (HAWT). This research studies about the optimization of DAWT using the preliminary design based on Kannan et al's research, it was showed that the final wind speed 61.25% increases over the inlet speed. In this paper, we propose a method that combines preliminary design with varies on the size of flange and inlet shroud using ANSYS software simulation to observe the fluid flow phenomenon in both inside and outside of the diffuser. The simulation boundary conditions refers to Abe and Ohya studies while the diffuser design to be tested refers to T. S. Kannan et al with the addition of small inner diffuser splitter. The best result reaches when combining the performance of inlet shroud and flange with the specific of 0.125D radius and 40° arc angle of inlet shroud, and 0.375D in height of the flange. This design has a total magnification until 1.8575 times or 85.75% increases over the inlet speed.