This page has only limited features, please log in for full access.
Flow control device modeling is an engaging research field for wind turbine optimization, since in recent years wind turbines have grown in proportions and weight. The purpose of the present work was to study the performance and effects generated by a rotating microtab (MT) implemented on the trailing edge of a DU91W250 airfoil through the novel cell-set (CS) model for the first time via CFD techniques. The CS method is based on the reutilization of an already calculated mesh for the addition of new geometries on it. To accomplish that objective, the required region is split from the main domain, and new boundaries are assigned to the mentioned construction. Three different MT lengths were considered: h = 1%, 1.5% and 2% of the airfoil chord length, as well as seven MT orientations (β): from 0° to −90° regarding the horizontal axis, for five angles of attack: 0°, 2°, 4°, 6° and 9°. The numerical results showed that the increases of the β rotating angle and the MT length (h) led to higher aerodynamic performance of the airfoil, CL/CD = 164.10 being the maximum ratio obtained. All the performance curves showed an asymptotic trend as the β angle reduced. Qualitatively, the model behaved as expected, proving the relationship between velocity and pressure. Taking into consideration resulting data, the cell-set method is appropriate for computational testing of trailing edge rotating microtab geometry.
Alejandro Ballesteros-Coll; Koldo Portal-Porras; Unai Fernandez-Gamiz; Ekaitz Zulueta; Jose Manuel Lopez-Guede. Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model. Sustainability 2021, 13, 9114 .
AMA StyleAlejandro Ballesteros-Coll, Koldo Portal-Porras, Unai Fernandez-Gamiz, Ekaitz Zulueta, Jose Manuel Lopez-Guede. Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model. Sustainability. 2021; 13 (16):9114.
Chicago/Turabian StyleAlejandro Ballesteros-Coll; Koldo Portal-Porras; Unai Fernandez-Gamiz; Ekaitz Zulueta; Jose Manuel Lopez-Guede. 2021. "Rotating Microtab Implementation on a DU91W250 Airfoil Based on the Cell-Set Model." Sustainability 13, no. 16: 9114.
Microtabs (MTs) are a regularly used flow control device in terms of wind turbine optimization. The present study introduces the application of the novel cell-set model for an MT implementation on a DU91W(2)250 airfoil. The cell-set model is based on the reusability of a mesh to add new geometries on the domain; the matching geometry is located where the user requires, and a set of cells is constructed around the mentioned geometry. Subsequently, wall boundaries are assigned to the generated region. Computational simulations were carried out for fully mesh and cell-set models: MT lengths were set at 1.0%, 1.5% and 2.0% of the airfoil chord length (c) and the MTs were placed at 93% and 95% of c from the leading edge of the airfoil. Resulting data showed that the MT behavior was similar for both models with regard to aerodynamic performance curve representations. A global relative error of 3.784% was obtained for the cell-set model and a maximum relative error of 7.332% was determined. Qualitatively, both models generated significantly similar flow stream velocity wakes on the trailing edge area of the airfoil.
Alejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Iñigo Aramendia; Ekaitz Zulueta; José Antonio Ramos-Hernanz. Cell-Set Modelling for a Microtab Implementation on a DU91W(2)250 Airfoil. Energies 2020, 13, 6723 .
AMA StyleAlejandro Ballesteros-Coll, Unai Fernandez-Gamiz, Iñigo Aramendia, Ekaitz Zulueta, José Antonio Ramos-Hernanz. Cell-Set Modelling for a Microtab Implementation on a DU91W(2)250 Airfoil. Energies. 2020; 13 (24):6723.
Chicago/Turabian StyleAlejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Iñigo Aramendia; Ekaitz Zulueta; José Antonio Ramos-Hernanz. 2020. "Cell-Set Modelling for a Microtab Implementation on a DU91W(2)250 Airfoil." Energies 13, no. 24: 6723.
Passive flow control devices are included in the design of wind turbine blades in order to obtain better performance and reduce loads without consuming any external energy. Vortex Generators are one of the most popular flow control devices, whose main objective is to delay the flow separation and increase the maximum lift coefficient. Computational Fluid Dynamics (CFD) simulations of a Vortex Generator (VG) on a flat plate in negligible streamwise pressure gradient conditions with the fully-resolved mesh model and the cell-set model using Large Eddy Simulation (LES) and Reynolds-Averaged Navier–Stokes (RANS) were carried out, with the objective of evaluating the accuracy of the cell-set model taking the fully-resolved mesh model as benchmark. The implementation of the cell-set model entailed a considerable reduction of the number of cells, which entailed saving simulation time and resources. The coherent structures, vortex path, wall shear stress and size, strength and velocity profiles of the primary vortex have been analyzed. The results show good agreements between the fully-resolved mesh model and the cell-set mode with RANS in all the analyzed parameters. With LES, acceptable results were obtained in terms of coherent structures, vortex path and wall shear stress, but slight differences between models are visible in the size, strength and velocity profiles of the primary vortex. As this is considered the first application of the cell-set model on VGs, further research is proposed, since the implementation of the cell-set model can represent an advantage over the fully-resolved mesh model.
Iosu Ibarra-Udaeta; Koldo Portal-Porras; Alejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Javier Sancho. Accuracy of the Cell-Set Model on a Single Vane-Type Vortex Generator in Negligible Streamwise Pressure Gradient Flow with RANS and LES. Journal of Marine Science and Engineering 2020, 8, 982 .
AMA StyleIosu Ibarra-Udaeta, Koldo Portal-Porras, Alejandro Ballesteros-Coll, Unai Fernandez-Gamiz, Javier Sancho. Accuracy of the Cell-Set Model on a Single Vane-Type Vortex Generator in Negligible Streamwise Pressure Gradient Flow with RANS and LES. Journal of Marine Science and Engineering. 2020; 8 (12):982.
Chicago/Turabian StyleIosu Ibarra-Udaeta; Koldo Portal-Porras; Alejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Javier Sancho. 2020. "Accuracy of the Cell-Set Model on a Single Vane-Type Vortex Generator in Negligible Streamwise Pressure Gradient Flow with RANS and LES." Journal of Marine Science and Engineering 8, no. 12: 982.
Over the last few years, the advances in size and weight for wind turbines have led to the development of flow control devices. The current work presents an innovative method to model flow control devices based on a cell-set model, such as Gurney flaps (GFs). This model reuses the cells which are around the required geometry and a wall boundary condition is assigned to the generated region. Numerical simulations based on RANS equations and with have been performed. Firstly, a performance study of the cell-set model on GFs was carried out by comparing it with a fully mesh model of a DU91W250 airfoil. A global relative error of 1.13% was calculated. Secondly, optimum GF lengths were determined (from 0% to 2% of c) for a DU97W300 airfoil and an application of them. The results showed that for lower angles of attack (AoAs) larger GFs were needed, and as the AoA increased, the optimum GF length value decreased. For the purpose of studying the effects generated by two flow control devices (vortex generators (VGs) and optimum GF) working together, a triangular VG based on the jBAY model was implemented. Resulting data indicated, as expected, that when both flow control devices were implemented, higher CL and lower CD values appeared.
Alejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Iñigo Aramendia; Ekaitz Zulueta; Jose Lopez-Guede. Computational Methods for Modelling and Optimization of Flow Control Devices. Energies 2020, 13, 3710 .
AMA StyleAlejandro Ballesteros-Coll, Unai Fernandez-Gamiz, Iñigo Aramendia, Ekaitz Zulueta, Jose Lopez-Guede. Computational Methods for Modelling and Optimization of Flow Control Devices. Energies. 2020; 13 (14):3710.
Chicago/Turabian StyleAlejandro Ballesteros-Coll; Unai Fernandez-Gamiz; Iñigo Aramendia; Ekaitz Zulueta; Jose Lopez-Guede. 2020. "Computational Methods for Modelling and Optimization of Flow Control Devices." Energies 13, no. 14: 3710.