Numerical Investigation of loaded and unloaded diffuser equipped with a flange (original) (raw)

Simulation of Diffuser Augmented Wind Turbine performance

2016 World Congress on Sustainable Technologies (WCST), 2016

The main objective of this research is to optimize the diffuser design of Diffuser Augmented Wind Turbine (DAWT). Specifically, this study investigates the effect of different shapes of diffusers to develop the suitable diffuser parameter for the wind turbine power enhancement. For that purpose, two diffuser cases have been recommended as an effective design in increasing wind speed, using a validated model of a small commercial wind turbine (AMPAIR-300) in it were developed and each case is simulated and analyzed using design software Solid-works and Computational Fluid Dynamic (CFD) software Fluent-ANSYS-15, As per the study, for diffuser case-1,the diffuser splitter degrades the diffuser effect when its open angle higher than the diffuser open angle, for diffuser case-2 the diffuser splitter enhance the diffuser effect when its open angle lower than diffuser open angle, also adding inlet shroud directs the wind flow into the inlet of diffuser and the diffuser flange effect on the power enhancement was significant and also its induced axial load was significant, and it is recommended to study the optimum dimension of inlet shroud, diffuser flange and diffuser splitter to minimize the coefficient of thrust and to enhance the coefficient of power.

Numerical investigation of a Specially Designed Shrouded Wind Turbine with a flanged diffuser

The present study In this paper considers a new wind power technology called "DAWT" diffuser augmented wind turbine equipped with a brim "wind-lens" in order to investigate the aerodynamic performance characterized by this technology. To achieve this objective, many models of DAWT with different shroud dimensions have been numerically investigated using commercial CFD software's. Four types of compact-style DAWT were investigated experimentally. namely A-ii, B-ii, C-ii and S-ii type with different diffuser sectional shapes, length ratios L t /D and area ratios AR (exit area / throat area). The results showed that C-ii diffuser type of a cycloid curve for its sectional shape and with (L t /D =0.221 and AR =1.294) was the most promising shroud shape. It has been chosen in this thesis to investigate the effect of varying the radial tip clearance and the diffuser length on the aerodynamic performance of it. Three-dimensional transient Numerical Simulations were developed using the commercial CFD software ANSYS FLUENT, by solving the Unsteady Reynolds Averaged Navier-Stokes (URANS) equations. Since this type of wind turbines consists of not only rotating blades but also a diffuser shroud with a brim located at the exit section of the diffuser, the flow field around the turbine is highly complex and unsteady from the results in the present work, C-ii diffuser type of a cycloid curve for its sectional shape (with length to diameter ratio L t /D=0.221 and area ratio A R =1.294) showed a good performance characteristic with C p equal to 0.92 at its design tip-speed ratio (λ=4.3). The results also concluded that C-ii with a tip clearance of 10 mm increases the output power coefficient by a factor of 2.25 compared with an un-shrouded one for the same wind speed and the same turbine characteristics. Increasing or decreasing the tip clearance away from 10 mm is not recommended as it showed an obvious decrease in the power coefficient C p due to the wake vortex generated around the turbine.

Fabrication and Experimentation of Diffuser Augmented Wind Turbine

International Journal of Recent Technology and Engineering (IJRTE), 2019

Wind Energy is turning into a big supply of renewable energy throughout the globe. This ever increasing field can probably reach the limit of accessibility and utility with the wind energy facility sites and size of the turbine itself. Therefore, it's needed to develop wind capturing devices that may produce energy within the locations wherever typical horizontal axis wind turbines (HAWTs) are too unrealistic to put in and operate. A diffuser augmented wind turbine (DAWT) is one such invention. DAWTs increase the ability output of the rotor by increasing the wind speed into the rotor employing a duct. The main objective of the project is to analyze the flow through the diffuser by placing it in wind tunnel and further the results are compared with the computational results. The purpose of investigating the flow through, the diffuser is to find out the behavior of wind flow at the throat region of the diffuser. Numerical analysis of diffuser is performed using the tool ANSYS FLUE...