Print Email Facebook Twitter A numerical study on the blade-vortex interaction of a two-dimensional Darrieus-Savonius combined vertical axis wind turbine Title A numerical study on the blade-vortex interaction of a two-dimensional Darrieus-Savonius combined vertical axis wind turbine Author Pan, J. (TU Delft Wind Energy) Ferreira, Carlos (TU Delft Wind Energy) van Zuijlen, A.H. (TU Delft Aerodynamics) Date 2023 Abstract To investigate power losses of a Darrieus-Savonius combined vertical axis wind turbine (hybrid VAWT) associated with the interaction between blades and wake, it is crucial to understand the flow phenomena around the turbine. This study presents a two-dimensional numerical analysis of vortex dynamics for a hybrid VAWT. The integration of a Savonius rotor in the hybrid VAWT improves self-starting capability but introduces vortices that cause transient load fluctuations on the Darrieus blades. This study attempts to characterize the flow features around the hybrid VAWT and correlate them with the Darrieus blade force variation in one revolution. Results demonstrate the capability of numerical modeling in handling a wide range of operational conditions: the relevant position of Savonius and Darrieus blades (attachment angle γ = 0 ° − 90 ° ) and Savonius' tip speed ratio λS (0.2-0.8, varied Savonius' rotational speed). The torque increase in the Darrieus blade in hybrid VAWT (compared to a single Darrieus rotor) due to the appearance of the vortex shedding from the advanced Savonius blade is independent of the attachment angle and tip speed ratio. Apart from start-up and power performances of the hybrid VAWT, the most rapid force fluctuation is identified when the Darrieus blade interacts with Savonius' wake at γ = 0 ° and λ S = 0.8 , which is considered undesirable. Furthermore, attachment angles of 60 ° and 90 ° exhibit better power coefficients compared to those of 0 ° and 30 ° for the hybrid VAWT. This study contributes to a comprehensive understanding of flow dynamics in hybrid VAWTs, revealing the correlation between torque variation and vortex development. To reference this document use: http://resolver.tudelft.nl/uuid:ce7785ed-2f36-4b44-8b4d-446c3ca3e174 DOI https://doi.org/10.1063/5.0174394 ISSN 1070-6631 Source Physics of Fluids, 35 (12) Part of collection Institutional Repository Document type journal article Rights © 2023 J. Pan, Carlos Ferreira, A.H. van Zuijlen Files PDF 125152_1_5.0174394.pdf 12.12 MB Close viewer /islandora/object/uuid:ce7785ed-2f36-4b44-8b4d-446c3ca3e174/datastream/OBJ/view