Flow-Driven Rotor Simulations of Seyi-Chunlei Ducted Turbine

Abstract

This paper proposes an improved Clarkson Ducted Wind Turbine (DWT) design using a new diffuser based on the Selig S1223 airfoil at an angle of attack (AoA) of 20 degrees and a smaller tip clearance. This proposed design is hereby named Selig20 Clarkson Ducted Turbine or Seyi-Chunlei Ducted Turbine (SCDT) compared to the original Clarkson Ducted Wind Turbine (CDWT). In both SCDT and CDWT configurations, the rotor is placed a distance behind the throat of the duct. For in-depth analysis, we employ a flow-driven-rotor (FDR) model of a commercial CFD package, Simerics-MP+, based on unstructured-grid finite-volume solutions of Unsteady Reynolds-Averaged Navier-Stokes (URANS) equations for the flow field that are two-way fully coupled with a dynamic solution of the rigid-body rotation of the turbine rotor. The FDR model successfully predicts the optimal thrust coefficient, whereas the prescribed rotation model fails to do so. Although the optimal Cp predicted by the FDR model is fairly close to the prediction from the prescribed motion model, FDR is generally more accurate in predicting underperformance under ambient wind conditions away from the optimal tip speed ratio. FDR offers a new path to simulate ducted wind turbines in ambient wind conditions. The Seyi-Chunlei Ducted Turbine is confirmed to have a Cpt peak approximately 7% higher than that of the Clarkson DWT. SCDT also has a wider range of optimal tip speed ratios, enabling it to harvest more wind energy under ambient conditions.